From 80d42c3337fae01b56bf3e93330fc12f224cfc22 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 07:40:53 -0400
Subject: [PATCH 01/53] native: support bounded SQL metadata reads

---
 ...lass-wp-markdown-native-query-executor.php |  53 ++++++-
 .../class-wp-markdown-native-query-parser.php |   4 -
 ...p-markdown-native-schema-introspection.php | 136 ++++++++++++++++++
 tests/smoke-native-aggregates.php             |   5 +
 tests/smoke-native-plugin-schema-query.php    |  10 ++
 tests/smoke-native-query-parser.php           |  10 +-
 tests/smoke-native-residual-equality.php      |   5 +
 tests/smoke-native-scalar-clauses.php         |   8 ++
 8 files changed, 220 insertions(+), 11 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index aa56648..9d176bd 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -63,6 +63,10 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		if ( 1 === preg_match( '/^\s*(?:SHOW|DESCRIBE)\b/i', $request->sql() ) ) {
 			return $this->schema_introspection->execute( $request );
 		}
+		$information_schema = $this->schema_introspection->select_information_schema( $request );
+		if ( null !== $information_schema ) {
+			return $information_schema;
+		}
 		// The canonical store is a directory, not a named server database.
 		if ( 1 === preg_match( '/^\s*SELECT\s+DATABASE\s*\(\s*\)\s*;?\s*$/i', $request->sql() ) ) {
 			return WP_Markdown_Query_Result::selected(
@@ -70,6 +74,10 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 				array( array( 'name' => 'DATABASE()', 'table' => '', 'type' => 253 ) )
 			);
 		}
+		$json_valid = $this->tableless_json_valid( $request->sql() );
+		if ( null !== $json_valid ) {
+			return $json_valid;
+		}
 		if ( 1 === preg_match( '/^\s*SELECT\s+(@@(?:SESSION\.)?(IN_TRANSACTION|AUTOCOMMIT))\s*;?\s*$/i', $request->sql(), $match ) ) {
 			$column = $match[1];
 			$variable = strtolower( $match[2] );
@@ -116,6 +124,41 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		return $this->execute_plan( $plan );
 	}
 
+	/** Execute the bounded tableless scalar form without treating JSON as a table source. */
+	private function tableless_json_valid( string $sql ): ?WP_Markdown_Query_Result {
+		try {
+			$tokens = ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( rtrim( trim( $sql ), ';' ) );
+		} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
+			return null;
+		}
+		if ( 6 !== count( $tokens )
+			|| 0 !== strcasecmp( 'SELECT', (string) $tokens[0]->value() )
+			|| 0 !== strcasecmp( 'JSON_VALID', (string) $tokens[1]->value() )
+			|| WP_Markdown_Native_SQL_Token::LEFT_PAREN !== $tokens[2]->type()
+			|| WP_Markdown_Native_SQL_Token::RIGHT_PAREN !== $tokens[4]->type()
+			|| WP_Markdown_Native_SQL_Token::END !== $tokens[5]->type()
+		) {
+			return null;
+		}
+		$value = 0 === strcasecmp( 'NULL', (string) $tokens[3]->value() ) ? null : $tokens[3]->value();
+		if ( null !== $value && WP_Markdown_Native_SQL_Token::STRING !== $tokens[3]->type() ) {
+			return null;
+		}
+		$valid = null;
+		if ( null !== $value ) {
+			try {
+				json_decode( (string) $value, true, 512, JSON_THROW_ON_ERROR );
+				$valid = '1';
+			} catch ( JsonException ) {
+				$valid = '0';
+			}
+		}
+		return WP_Markdown_Query_Result::selected(
+			array( array( 'JSON_VALID(' . $tokens[3]->lexeme() . ')' => $valid ) ),
+			array( array( 'name' => 'JSON_VALID(' . $tokens[3]->lexeme() . ')', 'table' => '', 'type' => 8 ) )
+		);
+	}
+
 	private function execute_plan( WP_Markdown_Native_Query_Plan $plan, bool $allow_union = true ): WP_Markdown_Query_Result {
 		if ( $allow_union && null !== $plan->union() ) {
 			return $this->execute_union( $plan );
@@ -214,7 +257,7 @@ private function execute_plan( WP_Markdown_Native_Query_Plan $plan, bool $allow_
 			}
 		}
 		$pushdown = $this->pushdown( $predicates, $schema );
-		if ( array() !== $predicates && null === $pushdown && ! $this->allows_residual_scan( $predicates, $schema ) ) {
+		if ( array() !== $predicates && null === $pushdown && ! $this->allows_residual_scan( $predicates, $schema, PHP_INT_MAX !== $plan->limit() ) ) {
 			return $this->failure( 'unsupported_lookup', 'mdi-native requires one indexable predicate for a filtered query.' );
 		}
 		foreach ( $plan->order_by() as $item ) {
@@ -1631,7 +1674,7 @@ private function derived_source( WP_Markdown_Native_Query_Plan $plan, string $na
 	}
 
 	/** @param array<int,WP_Markdown_Native_Query_Predicate> $predicates */
-	private function allows_residual_scan( array $predicates, WP_Markdown_Native_Table_Schema $schema ): bool {
+	private function allows_residual_scan( array $predicates, WP_Markdown_Native_Table_Schema $schema, bool $bounded = false ): bool {
 		$indexed = $this->indexed_columns( $schema );
 		foreach ( $predicates as $predicate ) {
 			if ( null !== $predicate->cast() ) {
@@ -1667,6 +1710,12 @@ private function allows_residual_scan( array $predicates, WP_Markdown_Native_Tab
 				&& $schema->allows_filter( $column, $predicate->operator(), $predicate->values() ) ) {
 				continue;
 			}
+			// Providers already apply all schema-validated residual filters before
+			// ORDER/LIMIT. Do not require a separate lookup declaration merely
+			// because a bounded query combines ordinary text predicates.
+			if ( $bounded && $schema->allows_filter( $column, $predicate->operator(), $predicate->values() ) ) {
+				continue;
+			}
 			return false;
 		}
 		return array() !== $predicates;
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index 32d0678..69aa9d5 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -1235,10 +1235,6 @@ private function match_aggregate(): ?array {
 			$alias = $function . '(' . ( null === $column ? '*' : $column->name() ) . ')';
 			if ( $this->match_keyword( 'AS' ) ) {
 				$alias = $this->unqualified_identifier()->name();
-			} elseif ( 'MIN' !== $function ) {
-				// Existing native aggregate support requires an explicit result
-				// name. The calendar derived-source query is the bounded exception.
-				$this->unsupported( $this->current() );
 			}
 			return array(
 				'function' => $function,
diff --git a/inc/native/class-wp-markdown-native-schema-introspection.php b/inc/native/class-wp-markdown-native-schema-introspection.php
index 90eb1a2..b1c48c8 100644
--- a/inc/native/class-wp-markdown-native-schema-introspection.php
+++ b/inc/native/class-wp-markdown-native-schema-introspection.php
@@ -250,6 +250,142 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 			: $this->indexes( (string) $query->table(), $definition, $query->predicates() );
 	}
 
+	/**
+	 * Answer bounded information_schema catalog reads from registered native DDL.
+	 *
+	 * This is deliberately separate from physical-table SELECT planning: a native
+	 * directory has no server catalog to scan, so callers must name the requested
+	 * tables before catalog rows are materialized.
+	 */
+	public function select_information_schema( WP_Markdown_Query_Request $request ): ?WP_Markdown_Query_Result {
+		try {
+			$tokens = ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( rtrim( trim( $request->sql() ), ';' ) );
+			$position = 0;
+			$word = static function ( string $expected ) use ( &$tokens, &$position ): bool {
+				if ( 0 !== strcasecmp( $expected, (string) ( $tokens[ $position ] ?? null )?->value() ) ) {
+					return false;
+				}
+				++$position;
+				return true;
+			};
+			$identifier = static function () use ( &$tokens, &$position ): ?string {
+				$token = $tokens[ $position ] ?? null;
+				if ( ! $token instanceof WP_Markdown_Native_SQL_Token || ! in_array( $token->type(), array( WP_Markdown_Native_SQL_Token::WORD, WP_Markdown_Native_SQL_Token::KEYWORD, WP_Markdown_Native_SQL_Token::QUOTED_IDENTIFIER ), true ) ) {
+					return null;
+				}
+				++$position;
+				return (string) $token->value();
+			};
+			if ( ! $word( 'SELECT' ) ) {
+				return null;
+			}
+			$projection = array();
+			do {
+				$name = $identifier();
+				if ( null === $name ) {
+					return null;
+				}
+				$alias = $name;
+				if ( $word( 'AS' ) ) {
+					$alias = $identifier();
+					if ( null === $alias ) {
+						return null;
+					}
+				}
+				$projection[] = array( 'name' => strtoupper( $name ), 'alias' => $alias );
+			} while ( WP_Markdown_Native_SQL_Token::COMMA === ( $tokens[ $position ] ?? null )?->type() && ++$position );
+			if ( ! $word( 'FROM' ) || 0 !== strcasecmp( 'information_schema', (string) $identifier() ) || WP_Markdown_Native_SQL_Token::DOT !== ( $tokens[ $position ] ?? null )?->type() ) {
+				return null;
+			}
+			++$position;
+			$catalog = strtoupper( (string) $identifier() );
+			if ( ! in_array( $catalog, array( 'COLUMNS', 'TABLES' ), true ) ) {
+				return null;
+			}
+			if ( ! $word( 'WHERE' ) ) {
+				return $this->failure( 'unsupported_lookup', 'mdi-native requires a bounded information_schema table lookup.' );
+			}
+			$names = array();
+			$schema_match = false;
+			do {
+				$column = strtoupper( (string) $identifier() );
+				if ( 'TABLE_SCHEMA' === $column && WP_Markdown_Native_SQL_Token::EQUALS === ( $tokens[ $position ] ?? null )?->type() ) {
+					++$position;
+					$schema_match = $word( 'DATABASE' ) && WP_Markdown_Native_SQL_Token::LEFT_PAREN === ( $tokens[ $position ] ?? null )?->type() && WP_Markdown_Native_SQL_Token::RIGHT_PAREN === ( $tokens[ $position + 1 ] ?? null )?->type();
+					$position += $schema_match ? 2 : 0;
+				} elseif ( 'TABLE_NAME' === $column && ( $word( 'IN' ) || WP_Markdown_Native_SQL_Token::EQUALS === ( $tokens[ $position ] ?? null )?->type() ) ) {
+					if ( WP_Markdown_Native_SQL_Token::EQUALS === ( $tokens[ $position ] ?? null )?->type() ) {
+						++$position;
+						$token = $tokens[ $position++ ] ?? null;
+						if ( ! $token instanceof WP_Markdown_Native_SQL_Token || WP_Markdown_Native_SQL_Token::STRING !== $token->type() ) { return null; }
+						$names[] = (string) $token->value();
+					} else {
+						if ( WP_Markdown_Native_SQL_Token::LEFT_PAREN !== ( $tokens[ $position ] ?? null )?->type() ) { return null; }
+						++$position;
+						do {
+							$token = $tokens[ $position++ ] ?? null;
+							if ( ! $token instanceof WP_Markdown_Native_SQL_Token || WP_Markdown_Native_SQL_Token::STRING !== $token->type() ) { return null; }
+							$names[] = (string) $token->value();
+						} while ( WP_Markdown_Native_SQL_Token::COMMA === ( $tokens[ $position ] ?? null )?->type() && ++$position );
+						if ( WP_Markdown_Native_SQL_Token::RIGHT_PAREN !== ( $tokens[ $position ] ?? null )?->type() ) { return null; }
+						++$position;
+					}
+				} else {
+					return null;
+				}
+			} while ( $word( 'AND' ) );
+			if ( ! $schema_match || array() === $names || WP_Markdown_Native_SQL_Token::END !== ( $tokens[ $position ] ?? null )?->type() ) {
+				return $this->failure( 'unsupported_lookup', 'mdi-native requires a bounded information_schema table lookup.' );
+			}
+			$rows = array();
+			foreach ( array_values( array_unique( $names ) ) as $table ) {
+				$definition = $this->registry->definition( $table );
+				if ( null === $definition || array() === $definition ) {
+					continue;
+				}
+				$catalog_rows = 'COLUMNS' === $catalog ? $this->information_schema_columns( $table, $definition ) : array( $this->information_schema_table( $table ) );
+				foreach ( $catalog_rows as $catalog_row ) {
+					$row = array();
+					foreach ( $projection as $column ) {
+						if ( ! array_key_exists( $column['name'], $catalog_row ) ) {
+							return $this->failure( 'unsupported_column', 'mdi-native cannot report the requested information_schema column.' );
+						}
+						$row[ $column['alias'] ] = $catalog_row[ $column['name'] ];
+					}
+					$rows[] = $row;
+				}
+			}
+			return WP_Markdown_Query_Result::selected( $rows, array_map( static fn( array $column ): array => array( 'name' => $column['alias'], 'table' => '', 'type' => 253 ), $projection ) );
+		} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
+			return null;
+		}
+	}
+
+	/** @param array{columns:array<string,array<string,mixed>>,indexes:array<int,array<string,mixed>>} $definition @return array<int,array<string,int|string|null>> */
+	private function information_schema_columns( string $table, array $definition ): array {
+		$rows = array();
+		foreach ( $definition['columns'] as $position => $column ) {
+			$rows[] = array(
+				'TABLE_SCHEMA' => defined( 'DB_NAME' ) ? (string) DB_NAME : '',
+				'TABLE_NAME' => $table,
+				'COLUMN_NAME' => $position,
+				'ORDINAL_POSITION' => (string) ( count( $rows ) + 1 ),
+				'COLUMN_DEFAULT' => $column['default'],
+				'IS_NULLABLE' => $column['nullable'] ? 'YES' : 'NO',
+				'DATA_TYPE' => strtolower( (string) $column['type'] ),
+				'COLUMN_TYPE' => $this->column_type( $column ),
+				'COLUMN_KEY' => $this->column_key( $position, $definition['indexes'] ),
+				'EXTRA' => $column['auto_increment'] ? 'auto_increment' : '',
+			);
+		}
+		return $rows;
+	}
+
+	/** @return array<string,string> */
+	private function information_schema_table( string $table ): array {
+		return array( 'TABLE_SCHEMA' => defined( 'DB_NAME' ) ? (string) DB_NAME : '', 'TABLE_NAME' => $table, 'ENGINE' => 'InnoDB', 'TABLE_TYPE' => 'BASE TABLE' );
+	}
+
 	/**
 	 * Report the server variables a file-backed engine can answer honestly.
 	 *
diff --git a/tests/smoke-native-aggregates.php b/tests/smoke-native-aggregates.php
index 2236223..ef8afed 100644
--- a/tests/smoke-native-aggregates.php
+++ b/tests/smoke-native-aggregates.php
@@ -40,6 +40,8 @@ function mdi_aggregate_row( WP_Markdown_Native_Query_Runtime $runtime, string $s
 $filtered = mdi_aggregate_row( $runtime, "SELECT SUM(score) AS total FROM wp_items WHERE kind = 'a'" );
 $empty = mdi_aggregate_row( $runtime, "SELECT SUM(score) AS total, COUNT(score) AS scored FROM wp_items WHERE kind = 'missing'" );
 $textual = mdi_aggregate_row( $runtime, 'SELECT SUM(kind) AS total FROM wp_items' );
+$default_names = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT MAX(score), COUNT(score) FROM wp_items', 'wp_' ) );
+$default_empty = $runtime->execute( new WP_Markdown_Query_Request( "SELECT MAX(score), COUNT(score) FROM wp_items WHERE kind = 'missing'", 'wp_' ) );
 
 $checks = array(
 	'one row reports every ungrouped aggregate' => array( 'total' => '60', 'mean' => '20', 'lowest' => '10', 'highest' => '30' ) === $totals,
@@ -48,6 +50,9 @@ function mdi_aggregate_row( WP_Markdown_Native_Query_Runtime $runtime, string $s
 	'a restriction narrows the aggregate' => array( 'total' => '40' ) === $filtered,
 	'an aggregate over no rows is NULL, and a count is zero' => array( 'total' => null, 'scored' => '0' ) === $empty,
 	'summing a text column stays fail-closed' => 'unsupported_aggregate' === ( $textual['unsupported'] ?? null ),
+	'unaliased column aggregates retain MySQL result names, values, and metadata' => array( 'MAX(score)' => '30', 'COUNT(score)' => '3' ) === (array) ( $default_names->wpdb_state()['last_result'][0] ?? array() )
+		&& array( 'MAX(score)', 'COUNT(score)' ) === array_map( static fn( object $column ): string => $column->name, $default_names->wpdb_state()['col_info'] ),
+	'unaliased column aggregates retain NULL and empty-set semantics' => array( 'MAX(score)' => null, 'COUNT(score)' => '0' ) === (array) ( $default_empty->wpdb_state()['last_result'][0] ?? array() ),
 );
 
 $failed = false;
diff --git a/tests/smoke-native-plugin-schema-query.php b/tests/smoke-native-plugin-schema-query.php
index bebb876..a09a2d0 100644
--- a/tests/smoke-native-plugin-schema-query.php
+++ b/tests/smoke-native-plugin-schema-query.php
@@ -120,6 +120,9 @@ function mdi_plugin_schema_remove_tree( string $root ): void {
 $show_full_columns = $runtime->execute( new WP_Markdown_Query_Request( 'SHOW FULL COLUMNS FROM wp_plugin_jobs' ) );
 $show_full_missing = $runtime->execute( new WP_Markdown_Query_Request( 'SHOW FULL COLUMNS FROM wp_missing' ) );
 $show_indexes = $runtime->execute( new WP_Markdown_Query_Request( 'SHOW INDEX FROM `wp_plugin_jobs`' ) );
+$information_columns = $runtime->execute( new WP_Markdown_Query_Request( "SELECT TABLE_NAME, COLUMN_NAME, ORDINAL_POSITION, COLUMN_DEFAULT, IS_NULLABLE, DATA_TYPE, COLUMN_TYPE, COLUMN_KEY, EXTRA FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME IN ('wp_plugin_jobs', 'wp_inline_items')" ) );
+$information_tables = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ENGINE AS Engine FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'wp_plugin_jobs'" ) );
+$unbounded_information = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT TABLE_NAME FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE()' ) );
 file_put_contents(
 	$root . '/_tables/plugin_jobs.json',
 	json_encode(
@@ -160,6 +163,13 @@ function mdi_plugin_schema_remove_tree( string $root ): void {
 		$show_indexes->wpdb_state()['last_result']
 	)
 		&& array( '0', '1' ) === array_map( static fn( object $row ): string => $row->Non_unique, $show_indexes->wpdb_state()['last_result'] ),
+	'bounded information_schema reads derive column and engine metadata from registered DDL' => array( 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_inline_items', 'wp_inline_items' ) === array_map( static fn( object $row ): string => $row->TABLE_NAME, $information_columns->wpdb_state()['last_result'] )
+		&& array( 'id', 'owner_id', 'status', 'task_url', 'owner_run_ref', 'payload' ) === array_map( static fn( object $row ): string => $row->COLUMN_NAME, array_slice( $information_columns->wpdb_state()['last_result'], 0, 6 ) )
+		&& 'PRI' === ( $information_columns->wpdb_state()['last_result'][0]->COLUMN_KEY ?? null )
+		&& 'InnoDB' === ( $information_tables->wpdb_state()['last_result'][0]->Engine ?? null )
+		&& array( 'Engine' ) === array_map( static fn( object $column ): string => $column->name, $information_tables->wpdb_state()['col_info'] ),
+	'information_schema catalog scans remain fail-closed without a bounded table name' => false === $unbounded_information->return_value()
+		&& 'unsupported_lookup' === ( $unbounded_information->diagnostic()['reason'] ?? null ),
 	'primary and secondary numeric indexes derive bounded lookup capabilities' => array( '1', '2' ) === array_map(
 		static fn( object $row ): string => $row->id,
 		$secondary->wpdb_state()['last_result']
diff --git a/tests/smoke-native-query-parser.php b/tests/smoke-native-query-parser.php
index ebe143c..66b5c8e 100644
--- a/tests/smoke-native-query-parser.php
+++ b/tests/smoke-native-query-parser.php
@@ -208,7 +208,9 @@
 		&& strpos( $unterminated_sql, "'open" ) === ( $unterminated->diagnostic()['sql_offset'] ?? null )
 		&& $malformed_and instanceof WP_Markdown_Query_Result
 		&& strpos( $malformed_and_sql, 'BY' ) === ( $malformed_and->diagnostic()['sql_offset'] ?? null ),
-	'an aliased column count is an aggregate like any other' => $counted_column instanceof WP_Markdown_Native_Query_Plan
+	'column counts retain typed aggregate plans with or without an alias' => $count_column instanceof WP_Markdown_Native_Query_Plan
+		&& 'COUNT(row_id)' === $count_column->aggregates()[0]['alias']
+		&& $counted_column instanceof WP_Markdown_Native_Query_Plan
 		&& 1 === count( $counted_column->aggregates() )
 		&& 'COUNT' === $counted_column->aggregates()[0]['function']
 		&& 'row_id' === $counted_column->aggregates()[0]['column'],
@@ -216,9 +218,7 @@
 		&& 'COUNT' === $distinct_count->aggregates()[0]['function']
 		&& 'row_id' === $distinct_count->aggregates()[0]['column']
 		&& true === $distinct_count->aggregates()[0]['distinct'],
-	'unsupported aggregate shapes fail closed at exact source positions' => $count_column instanceof WP_Markdown_Query_Result
-		&& strpos( $count_column_sql, 'FROM' ) === ( $count_column->diagnostic()['sql_offset'] ?? null )
-		&& $mixed_count instanceof WP_Markdown_Query_Result
+	'unsupported aggregate shapes fail closed at exact source positions' => $mixed_count instanceof WP_Markdown_Query_Result
 		&& strpos( $mixed_count_sql, ',' ) === ( $mixed_count->diagnostic()['sql_offset'] ?? null )
 		&& $aliased_count instanceof WP_Markdown_Query_Result
 		&& strpos( $aliased_count_sql, 'AS' ) === ( $aliased_count->diagnostic()['sql_offset'] ?? null )
@@ -227,7 +227,7 @@
 		&& $unsupported_function instanceof WP_Markdown_Query_Result
 		&& strpos( $unsupported_function_sql, '*' ) === ( $unsupported_function->diagnostic()['sql_offset'] ?? null )
 		&& array_reduce(
-			array( $count_column, $mixed_count, $aliased_count, $grouped_count, $unsupported_function ),
+			array( $mixed_count, $aliased_count, $grouped_count, $unsupported_function ),
 			static fn( bool $valid, WP_Markdown_Query_Result $result ): bool => $valid && 'unsupported_grammar' === ( $result->diagnostic()['reason'] ?? null ),
 			true
 		),
diff --git a/tests/smoke-native-residual-equality.php b/tests/smoke-native-residual-equality.php
index ec31af1..fc5d77f 100644
--- a/tests/smoke-native-residual-equality.php
+++ b/tests/smoke-native-residual-equality.php
@@ -20,6 +20,7 @@
 $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_yoast_indexable (object_id, object_type) VALUES (8, 'post')", 'wp_' ) );
 $hit = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT id, object_id FROM wp_yoast_indexable WHERE object_id = 7', 'wp_' ) );
 $miss = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT id FROM wp_yoast_indexable WHERE object_id = 404', 'wp_' ) );
+$ordered = $runtime->execute( new WP_Markdown_Query_Request( "SELECT id FROM wp_yoast_indexable WHERE object_type = 'post' ORDER BY id DESC LIMIT 1,1", 'wp_' ) );
 
 $checks = array(
 	'equality on a non-lookup integer column scans matching rows' => array( '7' ) === array_map(
@@ -28,6 +29,10 @@
 	),
 	'a residual equality miss is an empty success' => array() === $miss->wpdb_state()['last_result']
 		&& false !== $miss->return_value(),
+	'a bounded ordered text residual scan remains a successful native lookup' => array( '1' ) === array_map(
+		static fn( object $row ): string => (string) $row->id,
+		$ordered->wpdb_state()['last_result']
+	),
 );
 
 $failed = false;
diff --git a/tests/smoke-native-scalar-clauses.php b/tests/smoke-native-scalar-clauses.php
index 76fd30b..bfc2c81 100644
--- a/tests/smoke-native-scalar-clauses.php
+++ b/tests/smoke-native-scalar-clauses.php
@@ -32,6 +32,9 @@
 $calendar = $runtime->execute( new WP_Markdown_Query_Request( "SELECT DAYOFWEEK('2024-01-14') AS sunday, DAYOFMONTH(published_at) AS day, DAYOFYEAR(published_at) AS ordinal, WEEKDAY(published_at) AS weekday, WEEK(published_at, 1) AS week, SECOND(published_at) AS second, ABS(1 + 2 * 3) AS precedence FROM wp_dates WHERE id = 1", 'wp_' ) );
 $formatted = $runtime->execute( new WP_Markdown_Query_Request( "SELECT DATE_FORMAT('2021-01-01 13:02:03.123456', '%a|%W|%b|%M|%c|%D|%d|%e|%f|%H|%h|%I|%i|%j|%k|%l|%m|%p|%r|%S|%s|%T|%U|%u|%V|%v|%w|%X|%x|%Y|%y|%%|%q') AS formatted FROM wp_dates LIMIT 1", 'wp_' ) );
 $decimal = $runtime->execute( new WP_Markdown_Query_Request( "SELECT CAST('1.235' AS DECIMAL(5,2)) AS rounded, CAST('-1.235' AS DECIMAL(5,2)) AS negative, CAST('12.9' AS DECIMAL) AS default_decimal, CAST('1e3' AS DECIMAL(10,0)) AS exponent, CAST('0.125' AS DECIMAL(3,3)) AS fractional, CAST('-0.001' AS DECIMAL(3,2)) AS negative_zero, CAST('9999' AS DECIMAL(3,1)) AS overflow, CAST('99.96' AS DECIMAL(3,1)) AS round_overflow, SUBSTRING_INDEX('a,b,c', '', 1) AS empty_delimiter, SUBSTRING_INDEX('a,b,c', ',', 0) AS zero_count, SUBSTRING_INDEX('a,b,c', ',', -2) AS negative_count FROM wp_dates LIMIT 1", 'wp_' ) );
+$json_valid = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('{\"event\":true}')", 'wp_' ) );
+$json_invalid = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('{broken}')", 'wp_' ) );
+$json_null = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT JSON_VALID(NULL)', 'wp_' ) );
 $checks = array(
 	'WP date WHERE evaluates DATE_ADD INTERVAL after the bounded read' => array( '2', '3' ) === array_map( static fn( object $row ): string => $row->id, $where->wpdb_state()['last_result'] ),
 	'DATE_SUB INTERVAL and TIMESTAMPDIFF use the shared WHERE scalar path' => array( '1' ) === array_map( static fn( object $row ): string => $row->id, $subtracted->wpdb_state()['last_result'] )
@@ -60,6 +63,11 @@
 	'WP_Date_Query calendar parts and arithmetic precedence match MySQL' => array( 'sunday' => '1', 'day' => '15', 'ordinal' => '15', 'weekday' => '0', 'week' => '3', 'second' => '00', 'precedence' => '7' ) === (array) ( $calendar->wpdb_state()['last_result'][0] ?? array() ),
 	'DATE_FORMAT handles names, ordinals, 12-hour time, fractions, week modes, escapes, and unknown specifiers' => 'Fri|Friday|Jan|January|1|1st|01|1|123456|13|01|01|02|001|13|1|01|PM|01:02:03 PM|03|03|13:02:03|00|00|52|53|5|2020|2020|2021|21|%|q' === ( $formatted->wpdb_state()['last_result'][0]->formatted ?? null ),
 	'DECIMAL precision, exponents, saturation, and SUBSTRING_INDEX edge semantics match MariaDB' => array( 'rounded' => '1.24', 'negative' => '-1.24', 'default_decimal' => '13', 'exponent' => '1000', 'fractional' => '0.125', 'negative_zero' => '0.00', 'overflow' => '99.9', 'round_overflow' => '99.9', 'empty_delimiter' => '', 'zero_count' => '', 'negative_count' => 'b,c' ) === (array) ( $decimal->wpdb_state()['last_result'][0] ?? array() ),
+	'tableless JSON_VALID preserves valid, invalid, NULL, and column metadata semantics' => '1' === ( $json_valid->wpdb_state()['last_result'][0]->{'JSON_VALID(\'{"event":true}\')'} ?? null )
+		&& '0' === ( $json_invalid->wpdb_state()['last_result'][0]->{'JSON_VALID(\'{broken}\')'} ?? null )
+		&& null === ( $json_null->wpdb_state()['last_result'][0]->{'JSON_VALID(NULL)'} ?? null )
+		&& 'JSON_VALID(\'{"event":true}\')' === ( $json_valid->wpdb_state()['col_info'][0]->name ?? null )
+		&& 8 === ( $json_valid->wpdb_state()['col_info'][0]->type ?? null ),
 );
 $failed = false;
 foreach ( $checks as $label => $passed ) { echo ( $passed ? 'PASS: ' : 'FAIL: ' ) . $label . "\n"; $failed = $failed || ! $passed; }

From 42081b899f9520def6f9ef038389174ec59ff3c0 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 07:45:39 -0400
Subject: [PATCH 02/53] native: match bounded shadow SQL forms

---
 ...class-wp-markdown-native-query-executor.php | 16 ++++++++++++----
 .../class-wp-markdown-native-query-runtime.php |  2 +-
 ...wp-markdown-native-schema-introspection.php | 18 ++++++++++++++++++
 tests/smoke-native-plugin-schema-query.php     |  6 +++---
 tests/smoke-native-scalar-clauses.php          |  4 +++-
 5 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 9d176bd..2775512 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -131,15 +131,23 @@ private function tableless_json_valid( string $sql ): ?WP_Markdown_Query_Result
 		} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
 			return null;
 		}
-		if ( 6 !== count( $tokens )
+		$end = count( $tokens ) - 1;
+		if ( $end < 5
 			|| 0 !== strcasecmp( 'SELECT', (string) $tokens[0]->value() )
 			|| 0 !== strcasecmp( 'JSON_VALID', (string) $tokens[1]->value() )
 			|| WP_Markdown_Native_SQL_Token::LEFT_PAREN !== $tokens[2]->type()
 			|| WP_Markdown_Native_SQL_Token::RIGHT_PAREN !== $tokens[4]->type()
-			|| WP_Markdown_Native_SQL_Token::END !== $tokens[5]->type()
+			|| WP_Markdown_Native_SQL_Token::END !== $tokens[ $end ]->type()
 		) {
 			return null;
 		}
+		$column = 'JSON_VALID(' . $tokens[3]->lexeme() . ')';
+		if ( 5 < $end ) {
+			if ( 7 !== $end || 0 !== strcasecmp( 'AS', (string) $tokens[5]->value() ) || ! in_array( $tokens[6]->type(), array( WP_Markdown_Native_SQL_Token::WORD, WP_Markdown_Native_SQL_Token::KEYWORD, WP_Markdown_Native_SQL_Token::QUOTED_IDENTIFIER ), true ) ) {
+				return null;
+			}
+			$column = (string) $tokens[6]->value();
+		}
 		$value = 0 === strcasecmp( 'NULL', (string) $tokens[3]->value() ) ? null : $tokens[3]->value();
 		if ( null !== $value && WP_Markdown_Native_SQL_Token::STRING !== $tokens[3]->type() ) {
 			return null;
@@ -154,8 +162,8 @@ private function tableless_json_valid( string $sql ): ?WP_Markdown_Query_Result
 			}
 		}
 		return WP_Markdown_Query_Result::selected(
-			array( array( 'JSON_VALID(' . $tokens[3]->lexeme() . ')' => $valid ) ),
-			array( array( 'name' => 'JSON_VALID(' . $tokens[3]->lexeme() . ')', 'table' => '', 'type' => 8 ) )
+			array( array( $column => $valid ) ),
+			array( array( 'name' => $column, 'table' => '', 'type' => 8 ) )
 		);
 	}
 
diff --git a/inc/native/class-wp-markdown-native-query-runtime.php b/inc/native/class-wp-markdown-native-query-runtime.php
index f64c09c..8ed520b 100644
--- a/inc/native/class-wp-markdown-native-query-runtime.php
+++ b/inc/native/class-wp-markdown-native-query-runtime.php
@@ -111,7 +111,7 @@ public static function posts_schema(): WP_Markdown_Native_Table_Schema {
 						'lookup_validator' => static fn( array $values ): bool => self::all_ascii_strings( $values ),
 					),
 				),
-				'order_columns' => array( 'post_date', 'menu_order', 'post_title' ),
+				'order_columns' => array( 'post_date', 'post_date_gmt', 'menu_order', 'post_title' ),
 			)
 		);
 	}
diff --git a/inc/native/class-wp-markdown-native-schema-introspection.php b/inc/native/class-wp-markdown-native-schema-introspection.php
index b1c48c8..ade2529 100644
--- a/inc/native/class-wp-markdown-native-schema-introspection.php
+++ b/inc/native/class-wp-markdown-native-schema-introspection.php
@@ -306,6 +306,7 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 				return $this->failure( 'unsupported_lookup', 'mdi-native requires a bounded information_schema table lookup.' );
 			}
 			$names = array();
+			$column_names = array();
 			$schema_match = false;
 			do {
 				$column = strtoupper( (string) $identifier() );
@@ -313,6 +314,10 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 					++$position;
 					$schema_match = $word( 'DATABASE' ) && WP_Markdown_Native_SQL_Token::LEFT_PAREN === ( $tokens[ $position ] ?? null )?->type() && WP_Markdown_Native_SQL_Token::RIGHT_PAREN === ( $tokens[ $position + 1 ] ?? null )?->type();
 					$position += $schema_match ? 2 : 0;
+					if ( ! $schema_match && WP_Markdown_Native_SQL_Token::STRING === ( $tokens[ $position ] ?? null )?->type() ) {
+						$schema_match = true;
+						++$position;
+					}
 				} elseif ( 'TABLE_NAME' === $column && ( $word( 'IN' ) || WP_Markdown_Native_SQL_Token::EQUALS === ( $tokens[ $position ] ?? null )?->type() ) ) {
 					if ( WP_Markdown_Native_SQL_Token::EQUALS === ( $tokens[ $position ] ?? null )?->type() ) {
 						++$position;
@@ -330,6 +335,16 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 						if ( WP_Markdown_Native_SQL_Token::RIGHT_PAREN !== ( $tokens[ $position ] ?? null )?->type() ) { return null; }
 						++$position;
 					}
+				} elseif ( 'COLUMN_NAME' === $column && $word( 'IN' ) ) {
+					if ( WP_Markdown_Native_SQL_Token::LEFT_PAREN !== ( $tokens[ $position ] ?? null )?->type() ) { return null; }
+					++$position;
+					do {
+						$token = $tokens[ $position++ ] ?? null;
+						if ( ! $token instanceof WP_Markdown_Native_SQL_Token || WP_Markdown_Native_SQL_Token::STRING !== $token->type() ) { return null; }
+						$column_names[] = (string) $token->value();
+					} while ( WP_Markdown_Native_SQL_Token::COMMA === ( $tokens[ $position ] ?? null )?->type() && ++$position );
+					if ( WP_Markdown_Native_SQL_Token::RIGHT_PAREN !== ( $tokens[ $position ] ?? null )?->type() ) { return null; }
+					++$position;
 				} else {
 					return null;
 				}
@@ -345,6 +360,9 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 				}
 				$catalog_rows = 'COLUMNS' === $catalog ? $this->information_schema_columns( $table, $definition ) : array( $this->information_schema_table( $table ) );
 				foreach ( $catalog_rows as $catalog_row ) {
+					if ( array() !== $column_names && ! in_array( $catalog_row['COLUMN_NAME'] ?? null, $column_names, true ) ) {
+						continue;
+					}
 					$row = array();
 					foreach ( $projection as $column ) {
 						if ( ! array_key_exists( $column['name'], $catalog_row ) ) {
diff --git a/tests/smoke-native-plugin-schema-query.php b/tests/smoke-native-plugin-schema-query.php
index a09a2d0..dba5d60 100644
--- a/tests/smoke-native-plugin-schema-query.php
+++ b/tests/smoke-native-plugin-schema-query.php
@@ -120,7 +120,7 @@ function mdi_plugin_schema_remove_tree( string $root ): void {
 $show_full_columns = $runtime->execute( new WP_Markdown_Query_Request( 'SHOW FULL COLUMNS FROM wp_plugin_jobs' ) );
 $show_full_missing = $runtime->execute( new WP_Markdown_Query_Request( 'SHOW FULL COLUMNS FROM wp_missing' ) );
 $show_indexes = $runtime->execute( new WP_Markdown_Query_Request( 'SHOW INDEX FROM `wp_plugin_jobs`' ) );
-$information_columns = $runtime->execute( new WP_Markdown_Query_Request( "SELECT TABLE_NAME, COLUMN_NAME, ORDINAL_POSITION, COLUMN_DEFAULT, IS_NULLABLE, DATA_TYPE, COLUMN_TYPE, COLUMN_KEY, EXTRA FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME IN ('wp_plugin_jobs', 'wp_inline_items')" ) );
+$information_columns = $runtime->execute( new WP_Markdown_Query_Request( "SELECT TABLE_NAME, COLUMN_NAME, ORDINAL_POSITION, COLUMN_DEFAULT, IS_NULLABLE, DATA_TYPE, COLUMN_TYPE, COLUMN_KEY, EXTRA FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = 'wordpress' AND TABLE_NAME IN ('wp_plugin_jobs', 'wp_inline_items') AND COLUMN_NAME IN ('id', 'owner_id', 'value')" ) );
 $information_tables = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ENGINE AS Engine FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'wp_plugin_jobs'" ) );
 $unbounded_information = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT TABLE_NAME FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE()' ) );
 file_put_contents(
@@ -163,8 +163,8 @@ function mdi_plugin_schema_remove_tree( string $root ): void {
 		$show_indexes->wpdb_state()['last_result']
 	)
 		&& array( '0', '1' ) === array_map( static fn( object $row ): string => $row->Non_unique, $show_indexes->wpdb_state()['last_result'] ),
-	'bounded information_schema reads derive column and engine metadata from registered DDL' => array( 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_inline_items', 'wp_inline_items' ) === array_map( static fn( object $row ): string => $row->TABLE_NAME, $information_columns->wpdb_state()['last_result'] )
-		&& array( 'id', 'owner_id', 'status', 'task_url', 'owner_run_ref', 'payload' ) === array_map( static fn( object $row ): string => $row->COLUMN_NAME, array_slice( $information_columns->wpdb_state()['last_result'], 0, 6 ) )
+	'bounded information_schema reads derive column and engine metadata from registered DDL' => array( 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_inline_items', 'wp_inline_items' ) === array_map( static fn( object $row ): string => $row->TABLE_NAME, $information_columns->wpdb_state()['last_result'] )
+		&& array( 'id', 'owner_id', 'id', 'value' ) === array_map( static fn( object $row ): string => $row->COLUMN_NAME, $information_columns->wpdb_state()['last_result'] )
 		&& 'PRI' === ( $information_columns->wpdb_state()['last_result'][0]->COLUMN_KEY ?? null )
 		&& 'InnoDB' === ( $information_tables->wpdb_state()['last_result'][0]->Engine ?? null )
 		&& array( 'Engine' ) === array_map( static fn( object $column ): string => $column->name, $information_tables->wpdb_state()['col_info'] ),
diff --git a/tests/smoke-native-scalar-clauses.php b/tests/smoke-native-scalar-clauses.php
index bfc2c81..ceb2f9b 100644
--- a/tests/smoke-native-scalar-clauses.php
+++ b/tests/smoke-native-scalar-clauses.php
@@ -35,6 +35,7 @@
 $json_valid = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('{\"event\":true}')", 'wp_' ) );
 $json_invalid = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('{broken}')", 'wp_' ) );
 $json_null = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT JSON_VALID(NULL)', 'wp_' ) );
+$json_alias = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('[]') AS valid_json", 'wp_' ) );
 $checks = array(
 	'WP date WHERE evaluates DATE_ADD INTERVAL after the bounded read' => array( '2', '3' ) === array_map( static fn( object $row ): string => $row->id, $where->wpdb_state()['last_result'] ),
 	'DATE_SUB INTERVAL and TIMESTAMPDIFF use the shared WHERE scalar path' => array( '1' ) === array_map( static fn( object $row ): string => $row->id, $subtracted->wpdb_state()['last_result'] )
@@ -67,7 +68,8 @@
 		&& '0' === ( $json_invalid->wpdb_state()['last_result'][0]->{'JSON_VALID(\'{broken}\')'} ?? null )
 		&& null === ( $json_null->wpdb_state()['last_result'][0]->{'JSON_VALID(NULL)'} ?? null )
 		&& 'JSON_VALID(\'{"event":true}\')' === ( $json_valid->wpdb_state()['col_info'][0]->name ?? null )
-		&& 8 === ( $json_valid->wpdb_state()['col_info'][0]->type ?? null ),
+		&& 8 === ( $json_valid->wpdb_state()['col_info'][0]->type ?? null )
+		&& '1' === ( $json_alias->wpdb_state()['last_result'][0]->valid_json ?? null ),
 );
 $failed = false;
 foreach ( $checks as $label => $passed ) { echo ( $passed ? 'PASS: ' : 'FAIL: ' ) . $label . "\n"; $failed = $failed || ! $passed; }

From 8f5d577c95a46b149bab61683f4a49cf030008bb Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 08:04:21 -0400
Subject: [PATCH 03/53] native: support tableless scalar projections

---
 ...lass-wp-markdown-native-query-executor.php | 75 +++++++++++++------
 .../class-wp-markdown-native-query-parser.php | 55 +++++++++++++-
 ...ass-wp-markdown-native-shadow-verifier.php |  3 +-
 tests/smoke-native-scalar-clauses.php         |  6 +-
 tests/smoke-native-shadow-sql-snapshot.php    |  9 ++-
 5 files changed, 116 insertions(+), 32 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 2775512..8e64b90 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -74,9 +74,9 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 				array( array( 'name' => 'DATABASE()', 'table' => '', 'type' => 253 ) )
 			);
 		}
-		$json_valid = $this->tableless_json_valid( $request->sql() );
-		if ( null !== $json_valid ) {
-			return $json_valid;
+		$tableless = $this->tableless_scalar_projection( $request->sql() );
+		if ( null !== $tableless ) {
+			return $tableless;
 		}
 		if ( 1 === preg_match( '/^\s*SELECT\s+(@@(?:SESSION\.)?(IN_TRANSACTION|AUTOCOMMIT))\s*;?\s*$/i', $request->sql(), $match ) ) {
 			$column = $match[1];
@@ -124,7 +124,29 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		return $this->execute_plan( $plan );
 	}
 
-	/** Execute the bounded tableless scalar form without treating JSON as a table source. */
+	/** Execute source-free typed scalar expressions as the one-row SQL result. */
+	private function tableless_scalar_projection( string $sql ): ?WP_Markdown_Query_Result {
+		$projection = $this->parser->parse_tableless_scalar_projection( $sql );
+		if ( $projection instanceof WP_Markdown_Query_Result ) {
+			return $this->tableless_json_valid( $sql );
+		}
+		// The evaluator accepts a schema for CASE predicates; this sentinel is
+		// unreachable because tableless expressions have no column references.
+		$schema = new WP_Markdown_Native_Table_Schema(
+			array( '__mdi_native_tableless' => new WP_Markdown_Native_Column( 3, false ) ),
+			'__mdi_native_tableless'
+		);
+		$row = array();
+		$columns = array();
+		foreach ( $projection as $scalar ) {
+			$value = $this->evaluate_scalar( $scalar['expression'], array(), $schema );
+			$row[ $scalar['alias'] ] = $this->string_scalar( $value );
+			$columns[] = array( 'name' => $scalar['alias'], 'table' => '', 'type' => $this->tableless_scalar_type( $scalar['expression'], $value ) );
+		}
+		return WP_Markdown_Query_Result::selected( array( $row ), $columns );
+	}
+
+	/** Preserve the legacy unaliased JSON column label while typed aliases use the shared evaluator. */
 	private function tableless_json_valid( string $sql ): ?WP_Markdown_Query_Result {
 		try {
 			$tokens = ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( rtrim( trim( $sql ), ';' ) );
@@ -132,41 +154,36 @@ private function tableless_json_valid( string $sql ): ?WP_Markdown_Query_Result
 			return null;
 		}
 		$end = count( $tokens ) - 1;
-		if ( $end < 5
+		if ( $end !== 5
 			|| 0 !== strcasecmp( 'SELECT', (string) $tokens[0]->value() )
 			|| 0 !== strcasecmp( 'JSON_VALID', (string) $tokens[1]->value() )
 			|| WP_Markdown_Native_SQL_Token::LEFT_PAREN !== $tokens[2]->type()
 			|| WP_Markdown_Native_SQL_Token::RIGHT_PAREN !== $tokens[4]->type()
-			|| WP_Markdown_Native_SQL_Token::END !== $tokens[ $end ]->type()
+			|| WP_Markdown_Native_SQL_Token::END !== $tokens[5]->type()
 		) {
 			return null;
 		}
-		$column = 'JSON_VALID(' . $tokens[3]->lexeme() . ')';
-		if ( 5 < $end ) {
-			if ( 7 !== $end || 0 !== strcasecmp( 'AS', (string) $tokens[5]->value() ) || ! in_array( $tokens[6]->type(), array( WP_Markdown_Native_SQL_Token::WORD, WP_Markdown_Native_SQL_Token::KEYWORD, WP_Markdown_Native_SQL_Token::QUOTED_IDENTIFIER ), true ) ) {
-				return null;
-			}
-			$column = (string) $tokens[6]->value();
-		}
 		$value = 0 === strcasecmp( 'NULL', (string) $tokens[3]->value() ) ? null : $tokens[3]->value();
 		if ( null !== $value && WP_Markdown_Native_SQL_Token::STRING !== $tokens[3]->type() ) {
 			return null;
 		}
-		$valid = null;
-		if ( null !== $value ) {
-			try {
-				json_decode( (string) $value, true, 512, JSON_THROW_ON_ERROR );
-				$valid = '1';
-			} catch ( JsonException ) {
-				$valid = '0';
-			}
-		}
+		$column = 'JSON_VALID(' . $tokens[3]->lexeme() . ')';
 		return WP_Markdown_Query_Result::selected(
-			array( array( $column => $valid ) ),
-			array( array( 'name' => $column, 'table' => '', 'type' => 8 ) )
+			array( array( $column => null === $value ? null : $this->json_valid( (string) $value ) ) ),
+			array( array( 'name' => $column, 'table' => '', 'type' => 3 ) )
 		);
 	}
 
+	public static function supports_tableless_scalar_projection( string $sql ): bool {
+		return ! ( ( new WP_Markdown_Native_Query_Parser() )->parse_tableless_scalar_projection( $sql ) instanceof WP_Markdown_Query_Result );
+	}
+
+	private function tableless_scalar_type( WP_Markdown_Native_Query_Scalar_Expression $expression, int|string|null $value ): int {
+		if ( null === $value ) { return 6; }
+		if ( 'literal' === $expression->kind() ) { return is_int( $value ) ? 3 : ( is_numeric( $value ) ? 246 : 253 ); }
+		return 'JSON_VALID' === $expression->kind() ? 3 : 253;
+	}
+
 	private function execute_plan( WP_Markdown_Native_Query_Plan $plan, bool $allow_union = true ): WP_Markdown_Query_Result {
 		if ( $allow_union && null !== $plan->union() ) {
 			return $this->execute_union( $plan );
@@ -2011,6 +2028,7 @@ private function evaluate_scalar( WP_Markdown_Native_Query_Scalar_Expression $ex
 			'LOCATE' => in_array( null, $values, true ) ? null : ( false === strpos( (string) $values[1], (string) $values[0] ) ? 0 : strpos( (string) $values[1], (string) $values[0] ) + 1 ),
 			'MD5' => null === $values[0] ? null : md5( (string) $values[0] ),
 			'SHA1' => null === $values[0] ? null : sha1( (string) $values[0] ),
+			'JSON_VALID' => null === $values[0] ? null : $this->json_valid( (string) $values[0] ),
 			'ABS' => null === $values[0] ? null : $this->scalar_number( abs( $this->scalar_number( $values[0] ) ) ),
 			'ROUND' => null === $values[0] ? null : $this->scalar_number( round( $this->scalar_number( $values[0] ), (int) ( $values[1] ?? 0 ) ) ),
 			'FLOOR' => null === $values[0] ? null : $this->scalar_number( floor( $this->scalar_number( $values[0] ) ) ),
@@ -2043,6 +2061,15 @@ private function scalar_number( int|float|string|null $value ): int|string|null|
 		return floor( $number ) === $number ? (int) $number : (string) $number;
 	}
 
+	private function json_valid( string $value ): string {
+		try {
+			json_decode( $value, true, 512, JSON_THROW_ON_ERROR );
+			return '1';
+		} catch ( JsonException ) {
+			return '0';
+		}
+	}
+
 	/** Cast through decimal digits instead of PHP floats, which lose declared scale. */
 	private function cast_decimal( int|string $value, int|string $precision, int|string $scale ): string {
 		$precision = (int) $precision;
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index 69aa9d5..19dda07 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -22,6 +22,47 @@ public function parse( string $sql ): WP_Markdown_Native_Query_Plan|WP_Markdown_
 		}
 	}
 
+	/**
+	 * Parse scalar projections that have no row source without fabricating a
+	 * source schema. The synthetic FROM exists only to reuse the typed SELECT
+	 * grammar; all source-dependent plan shapes are rejected below.
+	 *
+	 * @return array<int,array{expression:WP_Markdown_Native_Query_Scalar_Expression,alias:string,position:int}>|WP_Markdown_Query_Result
+	 */
+	public function parse_tableless_scalar_projection( string $sql ): array|WP_Markdown_Query_Result {
+		$terminated = rtrim( $sql );
+		if ( str_ends_with( $terminated, ';' ) ) {
+			$terminated = rtrim( substr( $terminated, 0, -1 ) );
+		}
+		$plan = $this->parse( $terminated . ' FROM wp_mdi_native_tableless' );
+		if ( ! $plan instanceof WP_Markdown_Native_Query_Plan
+			|| 'wp_mdi_native_tableless' !== $plan->table()
+			|| array() !== $plan->projection()
+			|| array() === $plan->scalar_projection()
+			|| $plan->counts_all()
+			|| $plan->is_distinct()
+			|| array() !== $plan->joins()
+			|| array() !== $plan->predicates()
+			|| array() !== $plan->scalar_predicates()
+			|| null !== $plan->boolean_predicate()
+			|| array() !== $plan->aggregates()
+			|| null !== $plan->group_by()
+			|| array() !== $plan->order_by()
+			|| PHP_INT_MAX !== $plan->limit()
+			|| 0 !== $plan->limit_offset()
+		) {
+			return $plan instanceof WP_Markdown_Query_Result
+				? $plan
+				: $this->failure( 'unsupported_tableless_projection', 'mdi-native supports only source-free scalar SELECT projections.', 0 );
+		}
+		foreach ( $plan->scalar_projection() as $scalar ) {
+			if ( array() !== $scalar['expression']->columns() ) {
+				return $this->failure( 'unsupported_tableless_projection', 'mdi-native tableless scalar projections cannot reference columns.', 0 );
+			}
+		}
+		return $plan->scalar_projection();
+	}
+
 	public function parse_ast( string $sql ): WP_Markdown_Native_SQL_Select|WP_Markdown_Native_SQL_Found_Rows|WP_Markdown_Query_Result {
 		try {
 			// A single trailing statement terminator is not a second statement.
@@ -444,6 +485,14 @@ private function select( bool $nested ): WP_Markdown_Native_SQL_Select|WP_Markdo
 			$this->expect_type( WP_Markdown_Native_SQL_Token::RIGHT_PAREN );
 		} elseif ( ! $select_all ) {
 			do {
+				if ( $this->match_keyword( 'NULL' ) ) {
+					$scalar_projection[] = array(
+						'expression' => new WP_Markdown_Native_SQL_Scalar_Expression( 'literal', null, null ),
+						'alias' => $this->match_keyword( 'AS' ) ? $this->unqualified_identifier()->name() : 'NULL',
+						'position' => count( $projection ) + count( $scalar_projection ),
+					);
+					continue;
+				}
 				$aggregate = $this->match_aggregate();
 				if ( null !== $aggregate ) {
 					$aggregates[] = $aggregate;
@@ -461,7 +510,7 @@ private function select( bool $nested ): WP_Markdown_Native_SQL_Select|WP_Markdo
 					$literal = $this->literal();
 					$scalar_projection[] = array(
 						'expression' => new WP_Markdown_Native_SQL_Scalar_Expression( 'literal', null, $literal->value() ),
-						'alias' => (string) $literal->value(),
+						'alias' => $this->match_keyword( 'AS' ) ? $this->unqualified_identifier()->name() : (string) $literal->value(),
 						'position' => count( $projection ) + count( $scalar_projection ),
 					);
 					continue;
@@ -757,7 +806,7 @@ private function source( bool $base ): array {
 
 	private function matches_scalar_expression(): bool {
 		return WP_Markdown_Native_SQL_Token::LEFT_PAREN === $this->current()->type()
-			|| in_array( strtoupper( (string) $this->current()->value() ), array( 'CONCAT', 'COALESCE', 'SUBSTRING', 'SUBSTRING_INDEX', 'CAST', 'YEAR', 'MONTH', 'DATE_FORMAT', 'DATE', 'TIME', 'NOW', 'UTC_TIMESTAMP', 'CURDATE', 'UNIX_TIMESTAMP', 'FROM_UNIXTIME', 'DATEDIFF', 'TIMESTAMPDIFF', 'DATE_ADD', 'DATE_SUB', 'DAY', 'DAYOFMONTH', 'DAYOFYEAR', 'WEEKDAY', 'WEEK', 'SECOND', 'HOUR', 'MINUTE', 'DAYOFWEEK', 'GREATEST', 'LEAST', 'IF', 'IFNULL', 'NULLIF', 'LOWER', 'UPPER', 'TRIM', 'LENGTH', 'CHAR_LENGTH', 'REPLACE', 'LEFT', 'RIGHT', 'LOCATE', 'MD5', 'SHA1', 'ABS', 'ROUND', 'FLOOR', 'CEIL', 'MOD', 'POW', 'SQRT', 'RADIANS', 'DEGREES', 'SIN', 'COS', 'TAN', 'ACOS', 'ASIN', 'ATAN', 'ATAN2', 'RAND' ), true )
+			|| in_array( strtoupper( (string) $this->current()->value() ), array( 'CONCAT', 'COALESCE', 'SUBSTRING', 'SUBSTRING_INDEX', 'CAST', 'YEAR', 'MONTH', 'DATE_FORMAT', 'DATE', 'TIME', 'NOW', 'UTC_TIMESTAMP', 'CURDATE', 'UNIX_TIMESTAMP', 'FROM_UNIXTIME', 'DATEDIFF', 'TIMESTAMPDIFF', 'DATE_ADD', 'DATE_SUB', 'DAY', 'DAYOFMONTH', 'DAYOFYEAR', 'WEEKDAY', 'WEEK', 'SECOND', 'HOUR', 'MINUTE', 'DAYOFWEEK', 'GREATEST', 'LEAST', 'IF', 'IFNULL', 'NULLIF', 'LOWER', 'UPPER', 'TRIM', 'LENGTH', 'CHAR_LENGTH', 'REPLACE', 'LEFT', 'RIGHT', 'LOCATE', 'MD5', 'SHA1', 'JSON_VALID', 'ABS', 'ROUND', 'FLOOR', 'CEIL', 'MOD', 'POW', 'SQRT', 'RADIANS', 'DEGREES', 'SIN', 'COS', 'TAN', 'ACOS', 'ASIN', 'ATAN', 'ATAN2', 'RAND' ), true )
 			&& WP_Markdown_Native_SQL_Token::LEFT_PAREN === ( $this->tokens[ $this->current + 1 ] ?? null )?->type()
 			|| ( WP_Markdown_Native_SQL_Token::KEYWORD === $this->current()->type() && 0 === strcasecmp( 'CASE', (string) $this->current()->value() ) );
 	}
@@ -836,7 +885,7 @@ private function scalar_expression(): WP_Markdown_Native_SQL_Scalar_Expression {
 		$valid = match ( $function ) {
 			'CONCAT', 'COALESCE' => 2 <= count( $arguments ),
 			'SUBSTRING', 'SUBSTRING_INDEX' => 3 === count( $arguments ),
-			'YEAR', 'MONTH', 'DATE', 'TIME', 'FROM_UNIXTIME', 'DAY', 'DAYOFMONTH', 'DAYOFYEAR', 'WEEKDAY', 'SECOND', 'HOUR', 'MINUTE', 'DAYOFWEEK', 'LOWER', 'UPPER', 'TRIM', 'LENGTH', 'CHAR_LENGTH', 'MD5', 'SHA1', 'ABS', 'FLOOR', 'CEIL', 'SQRT', 'RADIANS', 'DEGREES', 'SIN', 'COS', 'TAN', 'ACOS', 'ASIN', 'ATAN' => 1 === count( $arguments ),
+			'YEAR', 'MONTH', 'DATE', 'TIME', 'FROM_UNIXTIME', 'DAY', 'DAYOFMONTH', 'DAYOFYEAR', 'WEEKDAY', 'SECOND', 'HOUR', 'MINUTE', 'DAYOFWEEK', 'LOWER', 'UPPER', 'TRIM', 'LENGTH', 'CHAR_LENGTH', 'MD5', 'SHA1', 'JSON_VALID', 'ABS', 'FLOOR', 'CEIL', 'SQRT', 'RADIANS', 'DEGREES', 'SIN', 'COS', 'TAN', 'ACOS', 'ASIN', 'ATAN' => 1 === count( $arguments ),
 			'UNIX_TIMESTAMP', 'RAND' => 0 === count( $arguments ) || 1 === count( $arguments ),
 			'WEEK' => 2 === count( $arguments ) && 1 === (int) $arguments[1]->literal(),
 			'DATE_FORMAT', 'DATEDIFF', 'IFNULL', 'NULLIF', 'LEFT', 'RIGHT', 'LOCATE', 'MOD', 'POW', 'ATAN2' => 2 === count( $arguments ),
diff --git a/inc/native/class-wp-markdown-native-shadow-verifier.php b/inc/native/class-wp-markdown-native-shadow-verifier.php
index 4a0ed24..a12cb65 100644
--- a/inc/native/class-wp-markdown-native-shadow-verifier.php
+++ b/inc/native/class-wp-markdown-native-shadow-verifier.php
@@ -391,7 +391,8 @@ private function normalized_query_template( string $query ): string {
 	}
 
 	private function is_stateless_runtime_fast_path( string $query ): bool {
-		return 1 === preg_match( '/^\s*SELECT\s+DATABASE\s*\(\s*\)\s*;?\s*$/i', $query );
+		return 1 === preg_match( '/^\s*SELECT\s+DATABASE\s*\(\s*\)\s*;?\s*$/i', $query )
+			|| WP_Markdown_Native_Query_Runtime::supports_tableless_scalar_projection( $query );
 	}
 
 	private function has_unordered_unbounded_result( string $query ): bool {
diff --git a/tests/smoke-native-scalar-clauses.php b/tests/smoke-native-scalar-clauses.php
index ceb2f9b..7525d98 100644
--- a/tests/smoke-native-scalar-clauses.php
+++ b/tests/smoke-native-scalar-clauses.php
@@ -36,6 +36,7 @@
 $json_invalid = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('{broken}')", 'wp_' ) );
 $json_null = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT JSON_VALID(NULL)', 'wp_' ) );
 $json_alias = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('[]') AS valid_json", 'wp_' ) );
+$literals = $runtime->execute( new WP_Markdown_Query_Request( "SELECT 1 AS one, 'event' AS label, NULL AS missing", 'wp_' ) );
 $checks = array(
 	'WP date WHERE evaluates DATE_ADD INTERVAL after the bounded read' => array( '2', '3' ) === array_map( static fn( object $row ): string => $row->id, $where->wpdb_state()['last_result'] ),
 	'DATE_SUB INTERVAL and TIMESTAMPDIFF use the shared WHERE scalar path' => array( '1' ) === array_map( static fn( object $row ): string => $row->id, $subtracted->wpdb_state()['last_result'] )
@@ -68,8 +69,11 @@
 		&& '0' === ( $json_invalid->wpdb_state()['last_result'][0]->{'JSON_VALID(\'{broken}\')'} ?? null )
 		&& null === ( $json_null->wpdb_state()['last_result'][0]->{'JSON_VALID(NULL)'} ?? null )
 		&& 'JSON_VALID(\'{"event":true}\')' === ( $json_valid->wpdb_state()['col_info'][0]->name ?? null )
-		&& 8 === ( $json_valid->wpdb_state()['col_info'][0]->type ?? null )
+		&& 3 === ( $json_valid->wpdb_state()['col_info'][0]->type ?? null )
 		&& '1' === ( $json_alias->wpdb_state()['last_result'][0]->valid_json ?? null ),
+	'tableless numeric, string, and NULL literals preserve aliases, values, and MySQL field types' => array( 'one' => '1', 'label' => 'event', 'missing' => null ) === (array) ( $literals->wpdb_state()['last_result'][0] ?? array() )
+		&& array( 'one', 'label', 'missing' ) === array_map( static fn( object $column ): string => $column->name, $literals->wpdb_state()['col_info'] )
+		&& array( 3, 253, 6 ) === array_map( static fn( object $column ): int => $column->type, $literals->wpdb_state()['col_info'] ),
 );
 $failed = false;
 foreach ( $checks as $label => $passed ) { echo ( $passed ? 'PASS: ' : 'FAIL: ' ) . $label . "\n"; $failed = $failed || ! $passed; }
diff --git a/tests/smoke-native-shadow-sql-snapshot.php b/tests/smoke-native-shadow-sql-snapshot.php
index f7a6636..fd39f21 100644
--- a/tests/smoke-native-shadow-sql-snapshot.php
+++ b/tests/smoke-native-shadow-sql-snapshot.php
@@ -192,8 +192,9 @@ public function get_col_info( string $field ): array {
 	1,
 	array( 'input_mode' => 'sql_snapshot' )
 );
-$tableless->capture_input( 'SELECT 1', $database );
-$tableless->observe( 'SELECT 1', 1, $database );
+$database->result_rows( array( array( 'one' => '1' ) ), array( array( 'name' => 'one', 'type' => 3 ) ) );
+$tableless->capture_input( 'SELECT 1 AS one', $database );
+$tableless->observe( 'SELECT 1 AS one', 1, $database );
 $capture_count_at_bound = count( $database->source()->results );
 $bounded->capture_input( 'SELECT ID, post_title FROM wp_posts', $database );
 $bounded->observe( 'SELECT ID, post_title FROM wp_posts', 1, $database );
@@ -223,7 +224,9 @@ public function get_col_info( string $field ): array {
 	'validated non-WordPress-prefixed plugin tables compile by exact captured identity' => array( 'agents' ) === array_column( $plugin_table['tables'], 'table' ),
 	'absent blog-2 schemas remain explicit snapshot input limitations' => 'source_schema_unavailable' === $missing_schema_reason,
 	'capture does no source work after the observation cap and drops the matching observation' => $capture_count_at_bound === count( $database->source()->results ) && 1 === $bounded->report()['counts']['dropped'],
-	'tableless native SQL retains its parser unsupported diagnostic' => 'markdown_db_native_unsupported_query' === ( $tableless->report()['first_blocker']['native_diagnostic']['code'] ?? null ),
+	'tableless scalar SQL is independently compared through the stateless runtime path' => 1 === $tableless->report()['counts']['compatible']
+		&& 'native_runtime_fast_path' === ( $tableless->report()['context']['last_input_state']['read_connection'] ?? null )
+		&& array() === ( $tableless->report()['context']['last_input_state']['tables'] ?? null ),
 	'capture results are released after both schema and row reads' => array_reduce( $database->source()->results, static fn( bool $freed, MDI_Snapshot_Result $result ): bool => $freed && $result->freed, true ),
 );
 $failed = 0;

From 9b64bdf51cd38fea148a4c215a4fae99b20b73d9 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 08:07:13 -0400
Subject: [PATCH 04/53] test: trace native shadow runtime phases

---
 ...-markdown-native-authoritative-snapshot-runtime.php |  9 +++++++++
 inc/native/class-wp-markdown-native-query-executor.php |  9 +++++++++
 inc/native/class-wp-markdown-native-query-parser.php   |  9 +++++++++
 tests/run-mysql-shadow-corpus.php                      | 10 ++++++++--
 4 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
index 628d445..10369ac 100644
--- a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
+++ b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
@@ -14,6 +14,7 @@ final class WP_Markdown_Native_Authoritative_Snapshot_Runtime implements WP_Mark
 	public function __construct( private WP_Markdown_Query_Runtime $runtime, private array $provenance ) {}
 
 	public static function capture( object $database, string $sql, string $prefix ): self {
+		self::trace_runtime_phase( 'capture' );
 		$connection = method_exists( $database, 'markdown_db_mysql_connection' )
 			? $database->markdown_db_mysql_connection()
 			: ( $database->dbh ?? null );
@@ -45,6 +46,14 @@ public static function capture( object $database, string $sql, string $prefix ):
 		return new self( new WP_Markdown_Native_Query_Runtime( $registry ), $provenance );
 	}
 
+	private static function trace_runtime_phase( string $phase ): void {
+		$path = getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
+		if ( ! is_string( $path ) || '' === $path ) {
+			return;
+		}
+		file_put_contents( $path, json_encode( array( 'phase' => $phase, 'file_sha256' => hash_file( 'sha256', __FILE__ ) ), JSON_UNESCAPED_SLASHES ) . "\n", FILE_APPEND | LOCK_EX );
+	}
+
 	/** @return array<int,string> */
 	private static function schema_prefixes( object $database, string $prefix ): array {
 		$prefixes = array( $prefix );
diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 8e64b90..b45e169 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -56,6 +56,7 @@ public function __construct(
 	}
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
+		self::trace_runtime_phase( 'executor' );
 		$transaction_control = WP_Markdown_SQL_Classifier::transaction_control( $request->sql() );
 		if ( null !== $transaction_control ) {
 			return $this->execute_transaction_control( $transaction_control );
@@ -124,6 +125,14 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		return $this->execute_plan( $plan );
 	}
 
+	private static function trace_runtime_phase( string $phase ): void {
+		$path = getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
+		if ( ! is_string( $path ) || '' === $path ) {
+			return;
+		}
+		file_put_contents( $path, json_encode( array( 'phase' => $phase, 'file_sha256' => hash_file( 'sha256', __FILE__ ) ), JSON_UNESCAPED_SLASHES ) . "\n", FILE_APPEND | LOCK_EX );
+	}
+
 	/** Execute source-free typed scalar expressions as the one-row SQL result. */
 	private function tableless_scalar_projection( string $sql ): ?WP_Markdown_Query_Result {
 		$projection = $this->parser->parse_tableless_scalar_projection( $sql );
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index 19dda07..e5e8170 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -11,6 +11,7 @@ public function __construct(
 	) {}
 
 	public function parse( string $sql ): WP_Markdown_Native_Query_Plan|WP_Markdown_Native_Found_Rows_Plan|WP_Markdown_Query_Result {
+		self::trace_runtime_phase( 'parser' );
 		$ast = $this->parse_ast( $sql );
 		if ( $ast instanceof WP_Markdown_Query_Result ) {
 			return $ast;
@@ -22,6 +23,14 @@ public function parse( string $sql ): WP_Markdown_Native_Query_Plan|WP_Markdown_
 		}
 	}
 
+	private static function trace_runtime_phase( string $phase ): void {
+		$path = getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
+		if ( ! is_string( $path ) || '' === $path ) {
+			return;
+		}
+		file_put_contents( $path, json_encode( array( 'phase' => $phase, 'file_sha256' => hash_file( 'sha256', __FILE__ ) ), JSON_UNESCAPED_SLASHES ) . "\n", FILE_APPEND | LOCK_EX );
+	}
+
 	/**
 	 * Parse scalar projections that have no row source without fabricating a
 	 * source schema. The synthetic FROM exists only to reuse the typed SELECT
diff --git a/tests/run-mysql-shadow-corpus.php b/tests/run-mysql-shadow-corpus.php
index 546d359..cf6ce4e 100644
--- a/tests/run-mysql-shadow-corpus.php
+++ b/tests/run-mysql-shadow-corpus.php
@@ -26,6 +26,8 @@
 $artifacts = $root . '/artifacts';
 $report_path = '/tmp/mdi-shadow-report.json';
 $report_name = 'mdi-shadow-report';
+$trace_path = '/tmp/mdi-shadow-runtime-trace.jsonl';
+$trace_name = 'mdi-shadow-runtime-trace';
 $revision = trim( (string) shell_exec( 'git -C ' . escapeshellarg( $repo ) . ' rev-parse HEAD' ) );
 mkdir( $bootstrap, 0755, true );
 mkdir( $state, 0755, true );
@@ -72,7 +74,8 @@
 			'MARKDOWN_DB_NATIVE_SHADOW' => 'true',
 			'MARKDOWN_DB_NATIVE_SHADOW_MAX' => '10000',
 			'MARKDOWN_DB_NATIVE_SHADOW_INPUT_MODE' => 'sql_snapshot',
-			'MARKDOWN_DB_NATIVE_SHADOW_REPORT_PATH' => $report_path,
+		'MARKDOWN_DB_NATIVE_SHADOW_REPORT_PATH' => $report_path,
+		'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' => $trace_path,
 		),
 		'services' => array( array(
 			'id' => 'mysql',
@@ -85,7 +88,10 @@
 		array(
 			'command' => 'wordpress.phpunit',
 			'args' => array_merge( array( 'plugin-slug=' . $plugin_slug, 'database-type=mysql', 'multisite=1' ), false === $harness_dir ? array() : array( 'autoload-file=/wordpress/wp-content/mdi-shadow-phpunit/autoload.php', 'tests-dir=/wordpress/wp-content/mdi-shadow-phpunit/wp-phpunit/wp-phpunit' ), array() === $dependency_mounts ? array() : array( 'dependency-mounts=' . implode( ',', $dependency_mounts ) ), $phpunit_args ),
-			'resultPaths' => array( array( 'name' => $report_name, 'type' => 'mdi-native-shadow-report/v1', 'path' => $report_path, 'required' => true, 'maxBytes' => 1048576 ) ),
+			'resultPaths' => array(
+				array( 'name' => $report_name, 'type' => 'mdi-native-shadow-report/v1', 'path' => $report_path, 'required' => true, 'maxBytes' => 1048576 ),
+				array( 'name' => $trace_name, 'type' => 'mdi-native-shadow-trace/v1', 'path' => $trace_path, 'required' => true, 'maxBytes' => 1048576 ),
+			),
 		),
 	) ),
 	'artifacts' => array( 'directory' => $artifacts ),

From abbaf140b7ce232451c7f51fc46a0290fb21298a Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 08:09:09 -0400
Subject: [PATCH 05/53] test: expose native shadow trace path

---
 db.php                                                      | 6 ++++++
 ...ss-wp-markdown-native-authoritative-snapshot-runtime.php | 2 +-
 inc/native/class-wp-markdown-native-query-executor.php      | 2 +-
 inc/native/class-wp-markdown-native-query-parser.php        | 2 +-
 tests/run-mysql-shadow-corpus.php                           | 4 ++--
 5 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/db.php b/db.php
index 3ca261e..fc866af 100644
--- a/db.php
+++ b/db.php
@@ -128,6 +128,12 @@ function markdown_database_integration_native_plugin_dir( string $content_dir ):
 		define( 'MARKDOWN_DB_NATIVE_SHADOW_REPORT_PATH', $markdown_db_shadow_report_path );
 	}
 }
+if ( ! defined( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' ) ) {
+	$markdown_db_shadow_trace_path = getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
+	if ( is_string( $markdown_db_shadow_trace_path ) && '' !== $markdown_db_shadow_trace_path ) {
+		define( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH', $markdown_db_shadow_trace_path );
+	}
+}
 
 // Downstream capability resolution, health, and CLI read the same identifier,
 // so the backend is settled before it is published. An operator who named a
diff --git a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
index 10369ac..a4a0b86 100644
--- a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
+++ b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
@@ -47,7 +47,7 @@ public static function capture( object $database, string $sql, string $prefix ):
 	}
 
 	private static function trace_runtime_phase( string $phase ): void {
-		$path = getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
+		$path = defined( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' ) ? MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH : getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
 		if ( ! is_string( $path ) || '' === $path ) {
 			return;
 		}
diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index b45e169..e4e5fc5 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -126,7 +126,7 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 	}
 
 	private static function trace_runtime_phase( string $phase ): void {
-		$path = getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
+		$path = defined( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' ) ? MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH : getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
 		if ( ! is_string( $path ) || '' === $path ) {
 			return;
 		}
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index e5e8170..0cf9189 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -24,7 +24,7 @@ public function parse( string $sql ): WP_Markdown_Native_Query_Plan|WP_Markdown_
 	}
 
 	private static function trace_runtime_phase( string $phase ): void {
-		$path = getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
+		$path = defined( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' ) ? MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH : getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
 		if ( ! is_string( $path ) || '' === $path ) {
 			return;
 		}
diff --git a/tests/run-mysql-shadow-corpus.php b/tests/run-mysql-shadow-corpus.php
index cf6ce4e..6f91db4 100644
--- a/tests/run-mysql-shadow-corpus.php
+++ b/tests/run-mysql-shadow-corpus.php
@@ -74,8 +74,8 @@
 			'MARKDOWN_DB_NATIVE_SHADOW' => 'true',
 			'MARKDOWN_DB_NATIVE_SHADOW_MAX' => '10000',
 			'MARKDOWN_DB_NATIVE_SHADOW_INPUT_MODE' => 'sql_snapshot',
-		'MARKDOWN_DB_NATIVE_SHADOW_REPORT_PATH' => $report_path,
-		'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' => $trace_path,
+			'MARKDOWN_DB_NATIVE_SHADOW_REPORT_PATH' => $report_path,
+			'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' => $trace_path,
 		),
 		'services' => array( array(
 			'id' => 'mysql',

From 387d20286a3f46cf7b2d77236875d4134fa52508 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 08:10:53 -0400
Subject: [PATCH 06/53] test: keep shadow tracing non-blocking

---
 tests/run-mysql-shadow-corpus.php | 2 --
 1 file changed, 2 deletions(-)

diff --git a/tests/run-mysql-shadow-corpus.php b/tests/run-mysql-shadow-corpus.php
index 6f91db4..ca5dc57 100644
--- a/tests/run-mysql-shadow-corpus.php
+++ b/tests/run-mysql-shadow-corpus.php
@@ -27,7 +27,6 @@
 $report_path = '/tmp/mdi-shadow-report.json';
 $report_name = 'mdi-shadow-report';
 $trace_path = '/tmp/mdi-shadow-runtime-trace.jsonl';
-$trace_name = 'mdi-shadow-runtime-trace';
 $revision = trim( (string) shell_exec( 'git -C ' . escapeshellarg( $repo ) . ' rev-parse HEAD' ) );
 mkdir( $bootstrap, 0755, true );
 mkdir( $state, 0755, true );
@@ -90,7 +89,6 @@
 			'args' => array_merge( array( 'plugin-slug=' . $plugin_slug, 'database-type=mysql', 'multisite=1' ), false === $harness_dir ? array() : array( 'autoload-file=/wordpress/wp-content/mdi-shadow-phpunit/autoload.php', 'tests-dir=/wordpress/wp-content/mdi-shadow-phpunit/wp-phpunit/wp-phpunit' ), array() === $dependency_mounts ? array() : array( 'dependency-mounts=' . implode( ',', $dependency_mounts ) ), $phpunit_args ),
 			'resultPaths' => array(
 				array( 'name' => $report_name, 'type' => 'mdi-native-shadow-report/v1', 'path' => $report_path, 'required' => true, 'maxBytes' => 1048576 ),
-				array( 'name' => $trace_name, 'type' => 'mdi-native-shadow-trace/v1', 'path' => $trace_path, 'required' => true, 'maxBytes' => 1048576 ),
 			),
 		),
 	) ),

From c4f7cdb17cb33eb27dac89db0910ff8f6a113546 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 08:21:28 -0400
Subject: [PATCH 07/53] fix(native): preserve catalog predicate semantics

---
 ...lass-wp-markdown-native-query-executor.php | 13 +++-
 ...p-markdown-native-schema-introspection.php | 71 ++++++++++++-------
 tests/smoke-native-plugin-schema-query.php    | 24 +++++--
 tests/smoke-native-server-introspection.php   |  3 +
 4 files changed, 75 insertions(+), 36 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index e4e5fc5..c93dc23 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -32,6 +32,8 @@ public function read( WP_Markdown_Native_Table_Access $access ): iterable|WP_Mar
 final class WP_Markdown_Native_Query_Runtime implements WP_Markdown_Query_Runtime {
 	private const MAX_JOIN_CANDIDATE_PAIRS = 100000;
 	private const MAX_CORRELATED_SUBQUERY_EVALUATIONS = 10000;
+	/** The largest SQL request accepted by the native request boundary. */
+	public const MAX_SQL_BYTES = 67108864;
 	private ?int $last_found_rows = null;
 	private ?string $statement_now = null;
 	/** @var array<string,array{values:array<string,true>,has_null:bool}> */
@@ -57,6 +59,9 @@ public function __construct(
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
 		self::trace_runtime_phase( 'executor' );
+		if ( strlen( $request->sql() ) > self::MAX_SQL_BYTES ) {
+			return $this->failure( 'request_too_large', 'mdi-native cannot execute a request larger than max_allowed_packet.' );
+		}
 		$transaction_control = WP_Markdown_SQL_Classifier::transaction_control( $request->sql() );
 		if ( null !== $transaction_control ) {
 			return $this->execute_transaction_control( $transaction_control );
@@ -79,12 +84,14 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		if ( null !== $tableless ) {
 			return $tableless;
 		}
-		if ( 1 === preg_match( '/^\s*SELECT\s+(@@(?:SESSION\.)?(IN_TRANSACTION|AUTOCOMMIT))\s*;?\s*$/i', $request->sql(), $match ) ) {
-			$column = $match[1];
+		if ( 1 === preg_match( '/^\s*SELECT\s+(@@(?:SESSION\.)?(IN_TRANSACTION|AUTOCOMMIT|MAX_ALLOWED_PACKET))(?:\s+AS\s+([A-Za-z_][A-Za-z0-9_]*))?\s*;?\s*$/i', $request->sql(), $match ) ) {
+			$column = $match[3] ?? $match[1];
 			$variable = strtolower( $match[2] );
 			$value = 'in_transaction' === $variable
 				? (string) (int) ( $this->transactions?->is_in_transaction() ?? false )
-				: (string) (int) ( $this->transactions?->is_autocommit() ?? true );
+				: ( 'autocommit' === $variable
+					? (string) (int) ( $this->transactions?->is_autocommit() ?? true )
+					: (string) self::MAX_SQL_BYTES );
 			return WP_Markdown_Query_Result::selected(
 				array( array( $column => $value ) ),
 				array( array( 'name' => $column, 'table' => '', 'type' => 8 ) )
diff --git a/inc/native/class-wp-markdown-native-schema-introspection.php b/inc/native/class-wp-markdown-native-schema-introspection.php
index ade2529..3f71ada 100644
--- a/inc/native/class-wp-markdown-native-schema-introspection.php
+++ b/inc/native/class-wp-markdown-native-schema-introspection.php
@@ -305,62 +305,61 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 			if ( ! $word( 'WHERE' ) ) {
 				return $this->failure( 'unsupported_lookup', 'mdi-native requires a bounded information_schema table lookup.' );
 			}
-			$names = array();
-			$column_names = array();
-			$schema_match = false;
+			$predicates = array();
 			do {
 				$column = strtoupper( (string) $identifier() );
+				$values = array();
+				if ( ! in_array( $column, array( 'TABLE_SCHEMA', 'TABLE_NAME', 'COLUMN_NAME' ), true ) ) {
+					return null;
+				}
 				if ( 'TABLE_SCHEMA' === $column && WP_Markdown_Native_SQL_Token::EQUALS === ( $tokens[ $position ] ?? null )?->type() ) {
 					++$position;
-					$schema_match = $word( 'DATABASE' ) && WP_Markdown_Native_SQL_Token::LEFT_PAREN === ( $tokens[ $position ] ?? null )?->type() && WP_Markdown_Native_SQL_Token::RIGHT_PAREN === ( $tokens[ $position + 1 ] ?? null )?->type();
-					$position += $schema_match ? 2 : 0;
-					if ( ! $schema_match && WP_Markdown_Native_SQL_Token::STRING === ( $tokens[ $position ] ?? null )?->type() ) {
-						$schema_match = true;
-						++$position;
+					if ( $word( 'DATABASE' ) && WP_Markdown_Native_SQL_Token::LEFT_PAREN === ( $tokens[ $position ] ?? null )?->type() && WP_Markdown_Native_SQL_Token::RIGHT_PAREN === ( $tokens[ $position + 1 ] ?? null )?->type() ) {
+						$values[] = defined( 'DB_NAME' ) ? (string) DB_NAME : '';
+						$position += 2;
+					} elseif ( WP_Markdown_Native_SQL_Token::STRING === ( $tokens[ $position ] ?? null )?->type() ) {
+						$values[] = (string) $tokens[ $position++ ]->value();
+					} else {
+						return null;
 					}
-				} elseif ( 'TABLE_NAME' === $column && ( $word( 'IN' ) || WP_Markdown_Native_SQL_Token::EQUALS === ( $tokens[ $position ] ?? null )?->type() ) ) {
+				} elseif ( ( 'TABLE_NAME' === $column || 'COLUMN_NAME' === $column ) && ( $word( 'IN' ) || WP_Markdown_Native_SQL_Token::EQUALS === ( $tokens[ $position ] ?? null )?->type() ) ) {
 					if ( WP_Markdown_Native_SQL_Token::EQUALS === ( $tokens[ $position ] ?? null )?->type() ) {
 						++$position;
 						$token = $tokens[ $position++ ] ?? null;
 						if ( ! $token instanceof WP_Markdown_Native_SQL_Token || WP_Markdown_Native_SQL_Token::STRING !== $token->type() ) { return null; }
-						$names[] = (string) $token->value();
+						$values[] = (string) $token->value();
 					} else {
 						if ( WP_Markdown_Native_SQL_Token::LEFT_PAREN !== ( $tokens[ $position ] ?? null )?->type() ) { return null; }
 						++$position;
 						do {
 							$token = $tokens[ $position++ ] ?? null;
 							if ( ! $token instanceof WP_Markdown_Native_SQL_Token || WP_Markdown_Native_SQL_Token::STRING !== $token->type() ) { return null; }
-							$names[] = (string) $token->value();
+							$values[] = (string) $token->value();
 						} while ( WP_Markdown_Native_SQL_Token::COMMA === ( $tokens[ $position ] ?? null )?->type() && ++$position );
 						if ( WP_Markdown_Native_SQL_Token::RIGHT_PAREN !== ( $tokens[ $position ] ?? null )?->type() ) { return null; }
 						++$position;
 					}
-				} elseif ( 'COLUMN_NAME' === $column && $word( 'IN' ) ) {
-					if ( WP_Markdown_Native_SQL_Token::LEFT_PAREN !== ( $tokens[ $position ] ?? null )?->type() ) { return null; }
-					++$position;
-					do {
-						$token = $tokens[ $position++ ] ?? null;
-						if ( ! $token instanceof WP_Markdown_Native_SQL_Token || WP_Markdown_Native_SQL_Token::STRING !== $token->type() ) { return null; }
-						$column_names[] = (string) $token->value();
-					} while ( WP_Markdown_Native_SQL_Token::COMMA === ( $tokens[ $position ] ?? null )?->type() && ++$position );
-					if ( WP_Markdown_Native_SQL_Token::RIGHT_PAREN !== ( $tokens[ $position ] ?? null )?->type() ) { return null; }
-					++$position;
 				} else {
 					return null;
 				}
+				$predicates[ $column ] = isset( $predicates[ $column ] ) ? array_values( array_intersect( $predicates[ $column ], $values ) ) : array_values( array_unique( $values ) );
 			} while ( $word( 'AND' ) );
-			if ( ! $schema_match || array() === $names || WP_Markdown_Native_SQL_Token::END !== ( $tokens[ $position ] ?? null )?->type() ) {
+			if ( ! isset( $predicates['TABLE_SCHEMA'], $predicates['TABLE_NAME'] ) || WP_Markdown_Native_SQL_Token::END !== ( $tokens[ $position ] ?? null )?->type() ) {
 				return $this->failure( 'unsupported_lookup', 'mdi-native requires a bounded information_schema table lookup.' );
 			}
+			$schema = defined( 'DB_NAME' ) ? (string) DB_NAME : '';
+			if ( ! in_array( $schema, $predicates['TABLE_SCHEMA'], true ) || array() === $predicates['TABLE_NAME'] ) {
+				return WP_Markdown_Query_Result::selected( array(), $this->information_schema_metadata( $projection, $catalog ) );
+			}
 			$rows = array();
-			foreach ( array_values( array_unique( $names ) ) as $table ) {
+			foreach ( $predicates['TABLE_NAME'] as $table ) {
 				$definition = $this->registry->definition( $table );
 				if ( null === $definition || array() === $definition ) {
 					continue;
 				}
 				$catalog_rows = 'COLUMNS' === $catalog ? $this->information_schema_columns( $table, $definition ) : array( $this->information_schema_table( $table ) );
 				foreach ( $catalog_rows as $catalog_row ) {
-					if ( array() !== $column_names && ! in_array( $catalog_row['COLUMN_NAME'] ?? null, $column_names, true ) ) {
+					if ( isset( $predicates['COLUMN_NAME'] ) && ! in_array( $catalog_row['COLUMN_NAME'] ?? null, $predicates['COLUMN_NAME'], true ) ) {
 						continue;
 					}
 					$row = array();
@@ -373,7 +372,7 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 					$rows[] = $row;
 				}
 			}
-			return WP_Markdown_Query_Result::selected( $rows, array_map( static fn( array $column ): array => array( 'name' => $column['alias'], 'table' => '', 'type' => 253 ), $projection ) );
+			return WP_Markdown_Query_Result::selected( $rows, $this->information_schema_metadata( $projection, $catalog ) );
 		} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
 			return null;
 		}
@@ -394,6 +393,7 @@ private function information_schema_columns( string $table, array $definition ):
 				'COLUMN_TYPE' => $this->column_type( $column ),
 				'COLUMN_KEY' => $this->column_key( $position, $definition['indexes'] ),
 				'EXTRA' => $column['auto_increment'] ? 'auto_increment' : '',
+				'CHARACTER_MAXIMUM_LENGTH' => null === $this->character_maximum_length( $column ) ? null : (string) $this->character_maximum_length( $column ),
 			);
 		}
 		return $rows;
@@ -401,7 +401,26 @@ private function information_schema_columns( string $table, array $definition ):
 
 	/** @return array<string,string> */
 	private function information_schema_table( string $table ): array {
-		return array( 'TABLE_SCHEMA' => defined( 'DB_NAME' ) ? (string) DB_NAME : '', 'TABLE_NAME' => $table, 'ENGINE' => 'InnoDB', 'TABLE_TYPE' => 'BASE TABLE' );
+		return array( 'TABLE_SCHEMA' => defined( 'DB_NAME' ) ? (string) DB_NAME : '', 'TABLE_NAME' => $table, 'TABLE_TYPE' => 'BASE TABLE' );
+	}
+
+	/** @param array<string,mixed> $column */
+	private function character_maximum_length( array $column ): ?int {
+		return in_array( strtolower( (string) $column['type'] ), array( 'char', 'varchar', 'binary', 'varbinary' ), true ) && is_int( $column['length'] )
+			? $column['length']
+			: null;
+	}
+
+	/** @param array<int,array{name:string,alias:string}> $projection @return array<int,array{name:string,type:int,table:string}> */
+	private function information_schema_metadata( array $projection, string $catalog ): array {
+		return array_map(
+			static fn( array $column ): array => array(
+				'name' => $column['alias'],
+				'table' => $catalog,
+				'type' => in_array( $column['name'], array( 'ORDINAL_POSITION', 'CHARACTER_MAXIMUM_LENGTH' ), true ) ? 8 : 253,
+			),
+			$projection
+		);
 	}
 
 	/**
diff --git a/tests/smoke-native-plugin-schema-query.php b/tests/smoke-native-plugin-schema-query.php
index dba5d60..96dbd26 100644
--- a/tests/smoke-native-plugin-schema-query.php
+++ b/tests/smoke-native-plugin-schema-query.php
@@ -4,6 +4,7 @@
 declare( strict_types=1 );
 
 define( 'ABSPATH', __DIR__ . '/' );
+define( 'DB_NAME', 'wordpress' );
 
 function apply_filters( string $tag, mixed $value, mixed ...$args ): mixed {
 	if ( 'markdown_db_table_durability_policy' === $tag && 'ephemeral_native' === ( $args[0] ?? null ) ) {
@@ -120,8 +121,11 @@ function mdi_plugin_schema_remove_tree( string $root ): void {
 $show_full_columns = $runtime->execute( new WP_Markdown_Query_Request( 'SHOW FULL COLUMNS FROM wp_plugin_jobs' ) );
 $show_full_missing = $runtime->execute( new WP_Markdown_Query_Request( 'SHOW FULL COLUMNS FROM wp_missing' ) );
 $show_indexes = $runtime->execute( new WP_Markdown_Query_Request( 'SHOW INDEX FROM `wp_plugin_jobs`' ) );
-$information_columns = $runtime->execute( new WP_Markdown_Query_Request( "SELECT TABLE_NAME, COLUMN_NAME, ORDINAL_POSITION, COLUMN_DEFAULT, IS_NULLABLE, DATA_TYPE, COLUMN_TYPE, COLUMN_KEY, EXTRA FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = 'wordpress' AND TABLE_NAME IN ('wp_plugin_jobs', 'wp_inline_items') AND COLUMN_NAME IN ('id', 'owner_id', 'value')" ) );
-$information_tables = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ENGINE AS Engine FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'wp_plugin_jobs'" ) );
+$information_columns = $runtime->execute( new WP_Markdown_Query_Request( "SELECT TABLE_NAME, COLUMN_NAME, ORDINAL_POSITION, CHARACTER_MAXIMUM_LENGTH, COLUMN_DEFAULT, IS_NULLABLE, DATA_TYPE, COLUMN_TYPE, COLUMN_KEY, EXTRA FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = 'wordpress' AND TABLE_NAME IN ('wp_plugin_jobs', 'wp_inline_items') AND COLUMN_NAME IN ('id', 'owner_id', 'status', 'value')" ) );
+$absent_information_schema = $runtime->execute( new WP_Markdown_Query_Request( "SELECT TABLE_NAME FROM information_schema.TABLES WHERE TABLE_SCHEMA = 'absent_schema' AND TABLE_NAME = 'wp_plugin_jobs'" ) );
+$contradictory_information_tables = $runtime->execute( new WP_Markdown_Query_Request( "SELECT TABLE_NAME FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'wp_plugin_jobs' AND TABLE_NAME = 'wp_inline_items'" ) );
+$contradictory_information_columns = $runtime->execute( new WP_Markdown_Query_Request( "SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'wp_plugin_jobs' AND COLUMN_NAME = 'id' AND COLUMN_NAME = 'status'" ) );
+$information_engine = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ENGINE AS Engine FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'wp_plugin_jobs'" ) );
 $unbounded_information = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT TABLE_NAME FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE()' ) );
 file_put_contents(
 	$root . '/_tables/plugin_jobs.json',
@@ -140,7 +144,7 @@ function mdi_plugin_schema_remove_tree( string $root ): void {
 		&& 'queued' === ( $exact->wpdb_state()['last_result'][0]->status ?? null )
 		&& '2' === ( $exact->wpdb_state()['last_result'][0]->id ?? null ),
 	'generic table introspection exposes registered tables with MySQL LIKE semantics' => 1 === $show_table->return_value()
-		&& 'wp_plugin_jobs' === ( $show_table->wpdb_state()['last_result'][0]->{'Tables_in_'} ?? null )
+		&& 'wp_plugin_jobs' === ( $show_table->wpdb_state()['last_result'][0]->Tables_in_wordpress ?? null )
 		&& 1 === $show_table_wildcard->return_value()
 		&& 1 === $show_table_escaped->return_value()
 		&& 0 === $show_missing_table->return_value(),
@@ -163,11 +167,17 @@ function mdi_plugin_schema_remove_tree( string $root ): void {
 		$show_indexes->wpdb_state()['last_result']
 	)
 		&& array( '0', '1' ) === array_map( static fn( object $row ): string => $row->Non_unique, $show_indexes->wpdb_state()['last_result'] ),
-	'bounded information_schema reads derive column and engine metadata from registered DDL' => array( 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_inline_items', 'wp_inline_items' ) === array_map( static fn( object $row ): string => $row->TABLE_NAME, $information_columns->wpdb_state()['last_result'] )
-		&& array( 'id', 'owner_id', 'id', 'value' ) === array_map( static fn( object $row ): string => $row->COLUMN_NAME, $information_columns->wpdb_state()['last_result'] )
+	'bounded information_schema reads derive column metadata from registered DDL' => array( 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_plugin_jobs', 'wp_inline_items', 'wp_inline_items' ) === array_map( static fn( object $row ): string => $row->TABLE_NAME, $information_columns->wpdb_state()['last_result'] )
+		&& array( 'id', 'owner_id', 'status', 'id', 'value' ) === array_map( static fn( object $row ): string => $row->COLUMN_NAME, $information_columns->wpdb_state()['last_result'] )
 		&& 'PRI' === ( $information_columns->wpdb_state()['last_result'][0]->COLUMN_KEY ?? null )
-		&& 'InnoDB' === ( $information_tables->wpdb_state()['last_result'][0]->Engine ?? null )
-		&& array( 'Engine' ) === array_map( static fn( object $column ): string => $column->name, $information_tables->wpdb_state()['col_info'] ),
+		&& '32' === ( $information_columns->wpdb_state()['last_result'][2]->CHARACTER_MAXIMUM_LENGTH ?? null )
+		&& null === ( $information_columns->wpdb_state()['last_result'][0]->CHARACTER_MAXIMUM_LENGTH ?? null )
+		&& array( 253, 253, 8, 8, 253, 253, 253, 253, 253, 253 ) === array_map( static fn( object $column ): int => $column->type, $information_columns->wpdb_state()['col_info'] ),
+	'information_schema predicates preserve schema equality and AND intersections' => 0 === $absent_information_schema->return_value()
+		&& 0 === $contradictory_information_tables->return_value()
+		&& 0 === $contradictory_information_columns->return_value(),
+	'information_schema does not manufacture a transactional storage engine' => false === $information_engine->return_value()
+		&& 'unsupported_column' === ( $information_engine->diagnostic()['reason'] ?? null ),
 	'information_schema catalog scans remain fail-closed without a bounded table name' => false === $unbounded_information->return_value()
 		&& 'unsupported_lookup' === ( $unbounded_information->diagnostic()['reason'] ?? null ),
 	'primary and secondary numeric indexes derive bounded lookup capabilities' => array( '1', '2' ) === array_map(
diff --git a/tests/smoke-native-server-introspection.php b/tests/smoke-native-server-introspection.php
index 4da0e6c..2e45452 100644
--- a/tests/smoke-native-server-introspection.php
+++ b/tests/smoke-native-server-introspection.php
@@ -23,12 +23,15 @@
 $liked_names = array_map( static fn( object $row ): string => (string) $row->Variable_name, $liked->wpdb_state()['last_result'] );
 $status = $runtime->execute( new WP_Markdown_Query_Request( "SHOW GLOBAL STATUS LIKE 'Uptime'", 'wp_' ) );
 $database = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT DATABASE()', 'wp_' ) );
+$max_allowed_packet = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT @@SESSION.max_allowed_packet as packet_limit', 'wp_' ) );
 $columns = array_map( static fn( object $column ): string => $column->name, $named->wpdb_state()['col_info'] );
 
 $checks = array(
 	'named variables report engine identity' => WP_Markdown_Native_Schema_Catalog::SERVER_VERSION === ( $variables['version'] ?? null )
 		&& array_key_exists( 'sql_mode', $variables ),
 	'a client/server tuning knob is absent rather than invented' => ! array_key_exists( 'max_allowed_packet', $variables ),
+	'SELECT session max_allowed_packet reports the native request boundary' => (string) WP_Markdown_Native_Query_Runtime::MAX_SQL_BYTES === ( $max_allowed_packet->wpdb_state()['last_result'][0]->packet_limit ?? null )
+		&& 8 === ( $max_allowed_packet->wpdb_state()['col_info'][0]->type ?? null ),
 	'LIKE selects matching variables' => array( 'character_set_server' ) === $liked_names,
 	'SHOW STATUS answers with a scoped qualifier' => array( 'Uptime' ) === array_map(
 		static fn( object $row ): string => (string) $row->Variable_name,

From 89e739ef3cd973df18206b1a45d79815fd44a404 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 10:29:36 -0400
Subject: [PATCH 08/53] fix(native): bound reviewed SQL semantics

---
 ...lass-wp-markdown-native-query-executor.php | 29 +++++++++----------
 ...p-markdown-native-schema-introspection.php | 26 +++++++++++++++--
 tests/smoke-native-plugin-schema-query.php    |  8 +++++
 tests/smoke-native-scalar-clauses.php         |  9 +++++-
 4 files changed, 52 insertions(+), 20 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 39fc5cd..6ecd1f4 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -63,6 +63,11 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		if ( strlen( $request->sql() ) > self::MAX_SQL_BYTES ) {
 			return $this->failure( 'request_too_large', 'mdi-native cannot execute a request larger than max_allowed_packet.' );
 		}
+		// Scalar functions share one statement scope, including tableless SELECTs.
+		$this->rand_states = array();
+		$this->correlated_subquery_cache = array();
+		$this->correlated_subquery_failure = null;
+		$this->statement_now = gmdate( 'Y-m-d H:i:s' );
 		$transaction_control = WP_Markdown_SQL_Classifier::transaction_control( $request->sql() );
 		if ( null !== $transaction_control ) {
 			return $this->execute_transaction_control( $transaction_control );
@@ -118,10 +123,6 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 				? $this->failure( 'unsupported_grammar', 'mdi-native supports bounded SELECT queries only.' )
 				: $this->option_mutations->execute( $request );
 		}
-		$this->rand_states = array();
-		$this->correlated_subquery_cache = array();
-		$this->correlated_subquery_failure = null;
-		$this->statement_now = gmdate( 'Y-m-d H:i:s' );
 		$plan = $this->parser->parse( $request->sql() );
 		if ( $plan instanceof WP_Markdown_Query_Result ) {
 			return $plan;
@@ -335,7 +336,7 @@ private function execute_plan( WP_Markdown_Native_Query_Plan $plan, bool $allow_
 			}
 		}
 		$pushdown = $this->pushdown( $predicates, $schema );
-		if ( array() !== $predicates && null === $pushdown && ! $this->allows_residual_scan( $predicates, $schema, PHP_INT_MAX !== $plan->limit() ) ) {
+		if ( array() !== $predicates && null === $pushdown && ! $this->allows_residual_scan( $predicates, $schema ) ) {
 			return $this->failure( 'unsupported_lookup', 'mdi-native requires one indexable predicate for a filtered query.' );
 		}
 		foreach ( $plan->order_by() as $item ) {
@@ -1752,7 +1753,7 @@ private function derived_source( WP_Markdown_Native_Query_Plan $plan, string $na
 	}
 
 	/** @param array<int,WP_Markdown_Native_Query_Predicate> $predicates */
-	private function allows_residual_scan( array $predicates, WP_Markdown_Native_Table_Schema $schema, bool $bounded = false ): bool {
+	private function allows_residual_scan( array $predicates, WP_Markdown_Native_Table_Schema $schema ): bool {
 		$indexed = $this->indexed_columns( $schema );
 		foreach ( $predicates as $predicate ) {
 			if ( null !== $predicate->cast() ) {
@@ -1788,12 +1789,6 @@ private function allows_residual_scan( array $predicates, WP_Markdown_Native_Tab
 				&& $schema->allows_filter( $column, $predicate->operator(), $predicate->values() ) ) {
 				continue;
 			}
-			// Providers already apply all schema-validated residual filters before
-			// ORDER/LIMIT. Do not require a separate lookup declaration merely
-			// because a bounded query combines ordinary text predicates.
-			if ( $bounded && $schema->allows_filter( $column, $predicate->operator(), $predicate->values() ) ) {
-				continue;
-			}
 			return false;
 		}
 		return array() !== $predicates;
@@ -2116,7 +2111,9 @@ private function scalar_number( int|float|string|null $value ): int|string|null|
 
 	private function json_valid( string $value ): string {
 		try {
-			json_decode( $value, true, 512, JSON_THROW_ON_ERROR );
+			// MariaDB 11.4 rejects JSON nesting at 32 levels; its parser counts
+			// the outermost array/object as the first level.
+			json_decode( $value, true, 32, JSON_THROW_ON_ERROR );
 			return '1';
 		} catch ( JsonException ) {
 			return '0';
@@ -2305,9 +2302,9 @@ private function rand( int|string|null $seed ): string {
 			return (string) ( random_int( 0, PHP_INT_MAX ) / PHP_INT_MAX );
 		}
 		$maximum = 0x3fffffff;
-		$key = (string) $seed;
-		$this->rand_states[ $key ] ??= array( 'seed1' => ( (int) $seed * 0x10001 + 55555555 ) % $maximum, 'seed2' => ( (int) $seed * 0x10000001 ) % $maximum );
-		$state = &$this->rand_states[ $key ];
+		// RAND(seed) reseeds for each expression evaluation, so two occurrences
+		// of the same seeded expression in one projection return the same value.
+		$state = array( 'seed1' => ( (int) $seed * 0x10001 + 55555555 ) % $maximum, 'seed2' => ( (int) $seed * 0x10000001 ) % $maximum );
 		$state['seed1'] = ( $state['seed1'] * 3 + $state['seed2'] ) % $maximum;
 		$state['seed2'] = ( $state['seed1'] + $state['seed2'] + 33 ) % $maximum;
 		return (string) ( $state['seed1'] / $maximum );
diff --git a/inc/native/class-wp-markdown-native-schema-introspection.php b/inc/native/class-wp-markdown-native-schema-introspection.php
index 3f71ada..7c0ef83 100644
--- a/inc/native/class-wp-markdown-native-schema-introspection.php
+++ b/inc/native/class-wp-markdown-native-schema-introspection.php
@@ -224,6 +224,9 @@ private function current(): WP_Markdown_Native_SQL_Token {
 }
 
 final class WP_Markdown_Native_Schema_Introspection {
+	private const MAX_INFORMATION_SCHEMA_PROJECTIONS = 32;
+	private const MAX_INFORMATION_SCHEMA_VALUES = 100;
+	private const MAX_INFORMATION_SCHEMA_ROWS = 1000;
 	public function __construct(
 		private readonly WP_Markdown_Native_Table_Registry $registry,
 		private readonly WP_Markdown_Native_Schema_Introspection_Parser $parser = new WP_Markdown_Native_Schema_Introspection_Parser()
@@ -281,6 +284,9 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 			}
 			$projection = array();
 			do {
+				if ( count( $projection ) >= self::MAX_INFORMATION_SCHEMA_PROJECTIONS ) {
+					return $this->failure( 'resource_limit', 'mdi-native limits information_schema projection cardinality.' );
+				}
 				$name = $identifier();
 				if ( null === $name ) {
 					return null;
@@ -332,6 +338,9 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 						if ( WP_Markdown_Native_SQL_Token::LEFT_PAREN !== ( $tokens[ $position ] ?? null )?->type() ) { return null; }
 						++$position;
 						do {
+							if ( count( $values ) >= self::MAX_INFORMATION_SCHEMA_VALUES ) {
+								return $this->failure( 'resource_limit', 'mdi-native limits information_schema predicate cardinality.' );
+							}
 							$token = $tokens[ $position++ ] ?? null;
 							if ( ! $token instanceof WP_Markdown_Native_SQL_Token || WP_Markdown_Native_SQL_Token::STRING !== $token->type() ) { return null; }
 							$values[] = (string) $token->value();
@@ -359,6 +368,9 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 				}
 				$catalog_rows = 'COLUMNS' === $catalog ? $this->information_schema_columns( $table, $definition ) : array( $this->information_schema_table( $table ) );
 				foreach ( $catalog_rows as $catalog_row ) {
+					if ( count( $rows ) >= self::MAX_INFORMATION_SCHEMA_ROWS ) {
+						return $this->failure( 'resource_limit', 'mdi-native limits information_schema result cardinality.' );
+					}
 					if ( isset( $predicates['COLUMN_NAME'] ) && ! in_array( $catalog_row['COLUMN_NAME'] ?? null, $predicates['COLUMN_NAME'], true ) ) {
 						continue;
 					}
@@ -406,9 +418,17 @@ private function information_schema_table( string $table ): array {
 
 	/** @param array<string,mixed> $column */
 	private function character_maximum_length( array $column ): ?int {
-		return in_array( strtolower( (string) $column['type'] ), array( 'char', 'varchar', 'binary', 'varbinary' ), true ) && is_int( $column['length'] )
-			? $column['length']
-			: null;
+		$type = strtolower( (string) $column['type'] );
+		if ( in_array( $type, array( 'char', 'varchar', 'binary', 'varbinary' ), true ) && is_int( $column['length'] ) ) {
+			return $column['length'];
+		}
+		return match ( $type ) {
+			'tinytext', 'tinyblob' => 255,
+			'text', 'blob' => 65535,
+			'mediumtext', 'mediumblob' => 16777215,
+			'longtext', 'longblob' => 4294967295,
+			default => null,
+		};
 	}
 
 	/** @param array<int,array{name:string,alias:string}> $projection @return array<int,array{name:string,type:int,table:string}> */
diff --git a/tests/smoke-native-plugin-schema-query.php b/tests/smoke-native-plugin-schema-query.php
index 96dbd26..ad1be2b 100644
--- a/tests/smoke-native-plugin-schema-query.php
+++ b/tests/smoke-native-plugin-schema-query.php
@@ -127,6 +127,9 @@ function mdi_plugin_schema_remove_tree( string $root ): void {
 $contradictory_information_columns = $runtime->execute( new WP_Markdown_Query_Request( "SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'wp_plugin_jobs' AND COLUMN_NAME = 'id' AND COLUMN_NAME = 'status'" ) );
 $information_engine = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ENGINE AS Engine FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'wp_plugin_jobs'" ) );
 $unbounded_information = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT TABLE_NAME FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE()' ) );
+$text_information = $runtime->execute( new WP_Markdown_Query_Request( "SELECT COLUMN_NAME, CHARACTER_MAXIMUM_LENGTH FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'wp_plugin_jobs' AND COLUMN_NAME IN ('task_url', 'payload')" ) );
+$overwide_information = $runtime->execute( new WP_Markdown_Query_Request( "SELECT TABLE_NAME FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME IN (" . implode( ',', array_fill( 0, 101, "'wp_plugin_jobs'" ) ) . ')' ) );
+$limited_residual = $runtime->execute( new WP_Markdown_Query_Request( "SELECT id FROM wp_plugin_jobs WHERE status = 'queued' LIMIT 1" ) );
 file_put_contents(
 	$root . '/_tables/plugin_jobs.json',
 	json_encode(
@@ -180,6 +183,11 @@ function mdi_plugin_schema_remove_tree( string $root ): void {
 		&& 'unsupported_column' === ( $information_engine->diagnostic()['reason'] ?? null ),
 	'information_schema catalog scans remain fail-closed without a bounded table name' => false === $unbounded_information->return_value()
 		&& 'unsupported_lookup' === ( $unbounded_information->diagnostic()['reason'] ?? null ),
+	'information_schema reports TEXT character maxima and bounds list cardinality' => array( 'task_url' => '65535', 'payload' => '4294967295' ) === array_reduce( $text_information->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() )
+		&& false === $overwide_information->return_value()
+		&& 'resource_limit' === ( $overwide_information->diagnostic()['reason'] ?? null ),
+	'finite result limits do not authorize unbounded residual source scans' => false === $limited_residual->return_value()
+		&& 'unsupported_lookup' === ( $limited_residual->diagnostic()['reason'] ?? null ),
 	'primary and secondary numeric indexes derive bounded lookup capabilities' => array( '1', '2' ) === array_map(
 		static fn( object $row ): string => $row->id,
 		$secondary->wpdb_state()['last_result']
diff --git a/tests/smoke-native-scalar-clauses.php b/tests/smoke-native-scalar-clauses.php
index 7525d98..6567ba6 100644
--- a/tests/smoke-native-scalar-clauses.php
+++ b/tests/smoke-native-scalar-clauses.php
@@ -36,6 +36,9 @@
 $json_invalid = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('{broken}')", 'wp_' ) );
 $json_null = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT JSON_VALID(NULL)', 'wp_' ) );
 $json_alias = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('[]') AS valid_json", 'wp_' ) );
+$json_depth_31 = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('" . str_repeat( '[', 31 ) . '0' . str_repeat( ']', 31 ) . "') AS valid_json", 'wp_' ) );
+$json_depth_32 = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('" . str_repeat( '[', 32 ) . '0' . str_repeat( ']', 32 ) . "') AS valid_json", 'wp_' ) );
+$statement_scalars = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT NOW() AS now_a, UTC_TIMESTAMP() AS now_b, RAND(1) AS rand_a, RAND(1) AS rand_b', 'wp_' ) );
 $literals = $runtime->execute( new WP_Markdown_Query_Request( "SELECT 1 AS one, 'event' AS label, NULL AS missing", 'wp_' ) );
 $checks = array(
 	'WP date WHERE evaluates DATE_ADD INTERVAL after the bounded read' => array( '2', '3' ) === array_map( static fn( object $row ): string => $row->id, $where->wpdb_state()['last_result'] ),
@@ -70,7 +73,11 @@
 		&& null === ( $json_null->wpdb_state()['last_result'][0]->{'JSON_VALID(NULL)'} ?? null )
 		&& 'JSON_VALID(\'{"event":true}\')' === ( $json_valid->wpdb_state()['col_info'][0]->name ?? null )
 		&& 3 === ( $json_valid->wpdb_state()['col_info'][0]->type ?? null )
-		&& '1' === ( $json_alias->wpdb_state()['last_result'][0]->valid_json ?? null ),
+		&& '1' === ( $json_alias->wpdb_state()['last_result'][0]->valid_json ?? null )
+		&& '1' === ( $json_depth_31->wpdb_state()['last_result'][0]->valid_json ?? null )
+		&& '0' === ( $json_depth_32->wpdb_state()['last_result'][0]->valid_json ?? null ),
+	'tableless scalar evaluation uses one fresh per-statement state' => ( $statement_scalars->wpdb_state()['last_result'][0]->now_a ?? null ) === ( $statement_scalars->wpdb_state()['last_result'][0]->now_b ?? null )
+		&& ( $statement_scalars->wpdb_state()['last_result'][0]->rand_a ?? null ) === ( $statement_scalars->wpdb_state()['last_result'][0]->rand_b ?? null ),
 	'tableless numeric, string, and NULL literals preserve aliases, values, and MySQL field types' => array( 'one' => '1', 'label' => 'event', 'missing' => null ) === (array) ( $literals->wpdb_state()['last_result'][0] ?? array() )
 		&& array( 'one', 'label', 'missing' ) === array_map( static fn( object $column ): string => $column->name, $literals->wpdb_state()['col_info'] )
 		&& array( 3, 253, 6 ) === array_map( static fn( object $column ): int => $column->type, $literals->wpdb_state()['col_info'] ),

From 610c39ecff3ac0032c94bd48f7180cf94c7c5bdf Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 11:28:41 -0400
Subject: [PATCH 09/53] fix(native): match MySQL JSON depth

---
 ...lass-wp-markdown-native-query-executor.php | 39 +++++++++++++++++--
 tests/smoke-native-scalar-clauses.php         | 12 ++++--
 2 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 6ecd1f4..389303c 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -161,6 +161,9 @@ private function tableless_scalar_projection( string $sql ): ?WP_Markdown_Query_
 		$row = array();
 		$columns = array();
 		foreach ( $projection as $scalar ) {
+			if ( 'JSON_VALID' === $scalar['expression']->kind() && $this->json_depth_exceeded( $scalar['expression'] ) ) {
+				return $this->mysql_json_depth_failure();
+			}
 			$value = $this->evaluate_scalar( $scalar['expression'], array(), $schema );
 			$row[ $scalar['alias'] ] = $this->string_scalar( $value );
 			$columns[] = array( 'name' => $scalar['alias'], 'table' => '', 'type' => $this->tableless_scalar_type( $scalar['expression'], $value ) );
@@ -190,6 +193,9 @@ private function tableless_json_valid( string $sql ): ?WP_Markdown_Query_Result
 			return null;
 		}
 		$column = 'JSON_VALID(' . $tokens[3]->lexeme() . ')';
+		if ( null !== $value && $this->json_depth_exceeded_value( (string) $value ) ) {
+			return $this->mysql_json_depth_failure();
+		}
 		return WP_Markdown_Query_Result::selected(
 			array( array( $column => null === $value ? null : $this->json_valid( (string) $value ) ) ),
 			array( array( 'name' => $column, 'table' => '', 'type' => 3 ) )
@@ -2111,15 +2117,42 @@ private function scalar_number( int|float|string|null $value ): int|string|null|
 
 	private function json_valid( string $value ): string {
 		try {
-			// MariaDB 11.4 rejects JSON nesting at 32 levels; its parser counts
-			// the outermost array/object as the first level.
-			json_decode( $value, true, 32, JSON_THROW_ON_ERROR );
+			// MySQL 8.4 accepts 100 containers and rejects the 101st. PHP counts
+			// the scalar below those containers too, hence the decode depth of 101.
+			json_decode( $value, true, 101, JSON_THROW_ON_ERROR );
 			return '1';
 		} catch ( JsonException ) {
 			return '0';
 		}
 	}
 
+	private function json_depth_exceeded( WP_Markdown_Native_Query_Scalar_Expression $expression ): bool {
+		$arguments = $expression->arguments();
+		if ( 1 !== count( $arguments ) || 'literal' !== $arguments[0]->kind() || ! is_string( $arguments[0]->literal() ) ) {
+			return false;
+		}
+		return $this->json_depth_exceeded_value( $arguments[0]->literal() );
+	}
+
+	private function json_depth_exceeded_value( string $value ): bool {
+		try {
+			json_decode( $value, true, 101, JSON_THROW_ON_ERROR );
+			return false;
+		} catch ( JsonException $error ) {
+			return JSON_ERROR_DEPTH === $error->getCode();
+		}
+	}
+
+	private function mysql_json_depth_failure(): WP_Markdown_Query_Result {
+		return WP_Markdown_Query_Result::failure(
+			array(
+				'code'    => 3157,
+				'reason'  => 'json_document_too_deep',
+				'message' => 'The JSON document exceeds the maximum depth.',
+			)
+		);
+	}
+
 	/** Cast through decimal digits instead of PHP floats, which lose declared scale. */
 	private function cast_decimal( int|string $value, int|string $precision, int|string $scale ): string {
 		$precision = (int) $precision;
diff --git a/tests/smoke-native-scalar-clauses.php b/tests/smoke-native-scalar-clauses.php
index 6567ba6..a69f8f9 100644
--- a/tests/smoke-native-scalar-clauses.php
+++ b/tests/smoke-native-scalar-clauses.php
@@ -36,8 +36,10 @@
 $json_invalid = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('{broken}')", 'wp_' ) );
 $json_null = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT JSON_VALID(NULL)', 'wp_' ) );
 $json_alias = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('[]') AS valid_json", 'wp_' ) );
-$json_depth_31 = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('" . str_repeat( '[', 31 ) . '0' . str_repeat( ']', 31 ) . "') AS valid_json", 'wp_' ) );
-$json_depth_32 = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('" . str_repeat( '[', 32 ) . '0' . str_repeat( ']', 32 ) . "') AS valid_json", 'wp_' ) );
+$json_array_depth_100 = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('" . str_repeat( '[', 100 ) . '0' . str_repeat( ']', 100 ) . "') AS valid_json", 'wp_' ) );
+$json_array_depth_101 = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('" . str_repeat( '[', 101 ) . '0' . str_repeat( ']', 101 ) . "') AS valid_json", 'wp_' ) );
+$json_object_depth_100 = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('" . str_repeat( '{\"key\":', 100 ) . '0' . str_repeat( '}', 100 ) . "') AS valid_json", 'wp_' ) );
+$json_object_depth_101 = $runtime->execute( new WP_Markdown_Query_Request( "SELECT JSON_VALID('" . str_repeat( '{\"key\":', 101 ) . '0' . str_repeat( '}', 101 ) . "') AS valid_json", 'wp_' ) );
 $statement_scalars = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT NOW() AS now_a, UTC_TIMESTAMP() AS now_b, RAND(1) AS rand_a, RAND(1) AS rand_b', 'wp_' ) );
 $literals = $runtime->execute( new WP_Markdown_Query_Request( "SELECT 1 AS one, 'event' AS label, NULL AS missing", 'wp_' ) );
 $checks = array(
@@ -74,8 +76,10 @@
 		&& 'JSON_VALID(\'{"event":true}\')' === ( $json_valid->wpdb_state()['col_info'][0]->name ?? null )
 		&& 3 === ( $json_valid->wpdb_state()['col_info'][0]->type ?? null )
 		&& '1' === ( $json_alias->wpdb_state()['last_result'][0]->valid_json ?? null )
-		&& '1' === ( $json_depth_31->wpdb_state()['last_result'][0]->valid_json ?? null )
-		&& '0' === ( $json_depth_32->wpdb_state()['last_result'][0]->valid_json ?? null ),
+		&& '1' === ( $json_array_depth_100->wpdb_state()['last_result'][0]->valid_json ?? null )
+		&& 3157 === ( $json_array_depth_101->wpdb_state()['last_errno'] ?? null )
+		&& '1' === ( $json_object_depth_100->wpdb_state()['last_result'][0]->valid_json ?? null )
+		&& 3157 === ( $json_object_depth_101->wpdb_state()['last_errno'] ?? null ),
 	'tableless scalar evaluation uses one fresh per-statement state' => ( $statement_scalars->wpdb_state()['last_result'][0]->now_a ?? null ) === ( $statement_scalars->wpdb_state()['last_result'][0]->now_b ?? null )
 		&& ( $statement_scalars->wpdb_state()['last_result'][0]->rand_a ?? null ) === ( $statement_scalars->wpdb_state()['last_result'][0]->rand_b ?? null ),
 	'tableless numeric, string, and NULL literals preserve aliases, values, and MySQL field types' => array( 'one' => '1', 'label' => 'event', 'missing' => null ) === (array) ( $literals->wpdb_state()['last_result'][0] ?? array() )

From 2a0aea37b069a614286c37037dcb035ded4a6ed7 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 11:32:50 -0400
Subject: [PATCH 10/53] test(shadow): retain token type traces

---
 ...own-native-authoritative-snapshot-runtime.php | 16 +++++++++++++---
 .../class-wp-markdown-native-query-executor.php  | 15 ++++++++++++---
 .../class-wp-markdown-native-query-parser.php    | 15 ++++++++++++---
 tests/run-mysql-shadow-corpus.php                |  2 ++
 4 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
index a6aa762..c253756 100644
--- a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
+++ b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
@@ -14,7 +14,7 @@ final class WP_Markdown_Native_Authoritative_Snapshot_Runtime implements WP_Mark
 	public function __construct( private WP_Markdown_Query_Runtime $runtime, private array $provenance ) {}
 
 	public static function capture( object $database, string $sql, string $prefix ): self {
-		self::trace_runtime_phase( 'capture' );
+		self::trace_runtime_phase( 'capture', $sql );
 		$connection = method_exists( $database, 'markdown_db_mysql_connection' )
 			? $database->markdown_db_mysql_connection()
 			: ( $database->dbh ?? null );
@@ -51,12 +51,22 @@ public static function capture( object $database, string $sql, string $prefix ):
 		return new self( new WP_Markdown_Native_Query_Runtime( $registry ), $provenance );
 	}
 
-	private static function trace_runtime_phase( string $phase ): void {
+	private static function trace_runtime_phase( string $phase, ?string $sql = null ): void {
 		$path = defined( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' ) ? MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH : getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
 		if ( ! is_string( $path ) || '' === $path ) {
 			return;
 		}
-		file_put_contents( $path, json_encode( array( 'phase' => $phase, 'file_sha256' => hash_file( 'sha256', __FILE__ ) ), JSON_UNESCAPED_SLASHES ) . "\n", FILE_APPEND | LOCK_EX );
+		$event = array( 'phase' => $phase, 'file_sha256' => hash_file( 'sha256', __FILE__ ) );
+		if ( null !== $sql ) {
+			try {
+				$event['sql_sha256'] = hash( 'sha256', $sql );
+				$event['token_types'] = array_map( static fn( WP_Markdown_Native_SQL_Token $token ): string => $token->type(), ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( $sql ) );
+				$event['table_count'] = count( self::tables_in( $sql ) );
+			} catch ( WP_Markdown_Native_Snapshot_Input_Exception|WP_Markdown_Native_SQL_Parse_Error ) {
+				$event['token_types'] = array( 'parse_error' );
+			}
+		}
+		file_put_contents( $path, json_encode( $event, JSON_UNESCAPED_SLASHES ) . "\n", FILE_APPEND | LOCK_EX );
 	}
 
 	/** @return array<int,string> */
diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 389303c..24b8eee 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -59,7 +59,7 @@ public function __construct(
 	}
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
-		self::trace_runtime_phase( 'executor' );
+		self::trace_runtime_phase( 'executor', $request->sql() );
 		if ( strlen( $request->sql() ) > self::MAX_SQL_BYTES ) {
 			return $this->failure( 'request_too_large', 'mdi-native cannot execute a request larger than max_allowed_packet.' );
 		}
@@ -138,12 +138,21 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		return $this->execute_plan( $plan );
 	}
 
-	private static function trace_runtime_phase( string $phase ): void {
+	private static function trace_runtime_phase( string $phase, ?string $sql = null ): void {
 		$path = defined( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' ) ? MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH : getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
 		if ( ! is_string( $path ) || '' === $path ) {
 			return;
 		}
-		file_put_contents( $path, json_encode( array( 'phase' => $phase, 'file_sha256' => hash_file( 'sha256', __FILE__ ) ), JSON_UNESCAPED_SLASHES ) . "\n", FILE_APPEND | LOCK_EX );
+		$event = array( 'phase' => $phase, 'file_sha256' => hash_file( 'sha256', __FILE__ ) );
+		if ( null !== $sql ) {
+			try {
+				$event['sql_sha256'] = hash( 'sha256', $sql );
+				$event['token_types'] = array_map( static fn( WP_Markdown_Native_SQL_Token $token ): string => $token->type(), ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( $sql ) );
+			} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
+				$event['token_types'] = array( 'parse_error' );
+			}
+		}
+		file_put_contents( $path, json_encode( $event, JSON_UNESCAPED_SLASHES ) . "\n", FILE_APPEND | LOCK_EX );
 	}
 
 	/** Execute source-free typed scalar expressions as the one-row SQL result. */
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index 0cf9189..c9b8223 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -11,7 +11,7 @@ public function __construct(
 	) {}
 
 	public function parse( string $sql ): WP_Markdown_Native_Query_Plan|WP_Markdown_Native_Found_Rows_Plan|WP_Markdown_Query_Result {
-		self::trace_runtime_phase( 'parser' );
+		self::trace_runtime_phase( 'parser', $sql );
 		$ast = $this->parse_ast( $sql );
 		if ( $ast instanceof WP_Markdown_Query_Result ) {
 			return $ast;
@@ -23,12 +23,21 @@ public function parse( string $sql ): WP_Markdown_Native_Query_Plan|WP_Markdown_
 		}
 	}
 
-	private static function trace_runtime_phase( string $phase ): void {
+	private static function trace_runtime_phase( string $phase, ?string $sql = null ): void {
 		$path = defined( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' ) ? MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH : getenv( 'MARKDOWN_DB_NATIVE_SHADOW_TRACE_PATH' );
 		if ( ! is_string( $path ) || '' === $path ) {
 			return;
 		}
-		file_put_contents( $path, json_encode( array( 'phase' => $phase, 'file_sha256' => hash_file( 'sha256', __FILE__ ) ), JSON_UNESCAPED_SLASHES ) . "\n", FILE_APPEND | LOCK_EX );
+		$event = array( 'phase' => $phase, 'file_sha256' => hash_file( 'sha256', __FILE__ ) );
+		if ( null !== $sql ) {
+			try {
+				$event['sql_sha256'] = hash( 'sha256', $sql );
+				$event['token_types'] = array_map( static fn( WP_Markdown_Native_SQL_Token $token ): string => $token->type(), ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( $sql ) );
+			} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
+				$event['token_types'] = array( 'parse_error' );
+			}
+		}
+		file_put_contents( $path, json_encode( $event, JSON_UNESCAPED_SLASHES ) . "\n", FILE_APPEND | LOCK_EX );
 	}
 
 	/**
diff --git a/tests/run-mysql-shadow-corpus.php b/tests/run-mysql-shadow-corpus.php
index ca5dc57..6f91db4 100644
--- a/tests/run-mysql-shadow-corpus.php
+++ b/tests/run-mysql-shadow-corpus.php
@@ -27,6 +27,7 @@
 $report_path = '/tmp/mdi-shadow-report.json';
 $report_name = 'mdi-shadow-report';
 $trace_path = '/tmp/mdi-shadow-runtime-trace.jsonl';
+$trace_name = 'mdi-shadow-runtime-trace';
 $revision = trim( (string) shell_exec( 'git -C ' . escapeshellarg( $repo ) . ' rev-parse HEAD' ) );
 mkdir( $bootstrap, 0755, true );
 mkdir( $state, 0755, true );
@@ -89,6 +90,7 @@
 			'args' => array_merge( array( 'plugin-slug=' . $plugin_slug, 'database-type=mysql', 'multisite=1' ), false === $harness_dir ? array() : array( 'autoload-file=/wordpress/wp-content/mdi-shadow-phpunit/autoload.php', 'tests-dir=/wordpress/wp-content/mdi-shadow-phpunit/wp-phpunit/wp-phpunit' ), array() === $dependency_mounts ? array() : array( 'dependency-mounts=' . implode( ',', $dependency_mounts ) ), $phpunit_args ),
 			'resultPaths' => array(
 				array( 'name' => $report_name, 'type' => 'mdi-native-shadow-report/v1', 'path' => $report_path, 'required' => true, 'maxBytes' => 1048576 ),
+				array( 'name' => $trace_name, 'type' => 'mdi-native-shadow-trace/v1', 'path' => $trace_path, 'required' => true, 'maxBytes' => 1048576 ),
 			),
 		),
 	) ),

From 26a7faefb7ff81baf00dcfe800d3d666bd525c3b Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 11:34:41 -0400
Subject: [PATCH 11/53] fix(shadow): keep runtime trace optional

---
 tests/run-mysql-shadow-corpus.php | 2 --
 1 file changed, 2 deletions(-)

diff --git a/tests/run-mysql-shadow-corpus.php b/tests/run-mysql-shadow-corpus.php
index 6f91db4..ca5dc57 100644
--- a/tests/run-mysql-shadow-corpus.php
+++ b/tests/run-mysql-shadow-corpus.php
@@ -27,7 +27,6 @@
 $report_path = '/tmp/mdi-shadow-report.json';
 $report_name = 'mdi-shadow-report';
 $trace_path = '/tmp/mdi-shadow-runtime-trace.jsonl';
-$trace_name = 'mdi-shadow-runtime-trace';
 $revision = trim( (string) shell_exec( 'git -C ' . escapeshellarg( $repo ) . ' rev-parse HEAD' ) );
 mkdir( $bootstrap, 0755, true );
 mkdir( $state, 0755, true );
@@ -90,7 +89,6 @@
 			'args' => array_merge( array( 'plugin-slug=' . $plugin_slug, 'database-type=mysql', 'multisite=1' ), false === $harness_dir ? array() : array( 'autoload-file=/wordpress/wp-content/mdi-shadow-phpunit/autoload.php', 'tests-dir=/wordpress/wp-content/mdi-shadow-phpunit/wp-phpunit/wp-phpunit' ), array() === $dependency_mounts ? array() : array( 'dependency-mounts=' . implode( ',', $dependency_mounts ) ), $phpunit_args ),
 			'resultPaths' => array(
 				array( 'name' => $report_name, 'type' => 'mdi-native-shadow-report/v1', 'path' => $report_path, 'required' => true, 'maxBytes' => 1048576 ),
-				array( 'name' => $trace_name, 'type' => 'mdi-native-shadow-trace/v1', 'path' => $trace_path, 'required' => true, 'maxBytes' => 1048576 ),
 			),
 		),
 	) ),

From 6cfcf4bef6a81b3ed833f8212c2a3594da149180 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 11:45:30 -0400
Subject: [PATCH 12/53] fix(shadow): capture tableless and catalog reads

---
 ...-native-authoritative-snapshot-runtime.php |  4 +
 ...lass-wp-markdown-native-query-executor.php | 35 +++++---
 ...p-markdown-native-schema-introspection.php | 80 +++++++++++++++++++
 ...ass-wp-markdown-native-shadow-verifier.php |  5 +-
 tests/smoke-native-shadow-sql-snapshot.php    | 30 +++++++
 5 files changed, 141 insertions(+), 13 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
index c253756..1851c7b 100644
--- a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
+++ b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
@@ -113,6 +113,10 @@ public function provenance(): array {
 	private static function tables_in( string $sql ): array {
 		$plan = ( new WP_Markdown_Native_Query_Parser() )->parse( $sql );
 		if ( $plan instanceof WP_Markdown_Query_Result ) {
+			$catalog_tables = WP_Markdown_Native_Schema_Introspection::requested_information_schema_tables( $sql );
+			if ( null !== $catalog_tables ) {
+				return $catalog_tables;
+			}
 			$diagnostic = $plan->diagnostic() ?? array();
 			throw new WP_Markdown_Native_Snapshot_Input_Exception(
 				(string) ( $diagnostic['code'] ?? 'markdown_db_native_unsupported_query' ),
diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 24b8eee..1bec5f7 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -182,6 +182,28 @@ private function tableless_scalar_projection( string $sql ): ?WP_Markdown_Query_
 
 	/** Preserve the legacy unaliased JSON column label while typed aliases use the shared evaluator. */
 	private function tableless_json_valid( string $sql ): ?WP_Markdown_Query_Result {
+		$literal = self::tableless_json_valid_literal( $sql );
+		if ( null === $literal ) {
+			return null;
+		}
+		$value = $literal['value'];
+		$column = $literal['column'];
+		if ( null !== $value && $this->json_depth_exceeded_value( (string) $value ) ) {
+			return $this->mysql_json_depth_failure();
+		}
+		return WP_Markdown_Query_Result::selected(
+			array( array( $column => null === $value ? null : $this->json_valid( (string) $value ) ) ),
+			array( array( 'name' => $column, 'table' => '', 'type' => 3 ) )
+		);
+	}
+
+	public static function supports_tableless_scalar_projection( string $sql ): bool {
+		return null !== self::tableless_json_valid_literal( $sql )
+			|| ! ( ( new WP_Markdown_Native_Query_Parser() )->parse_tableless_scalar_projection( $sql ) instanceof WP_Markdown_Query_Result );
+	}
+
+	/** @return array{value:?string,column:string}|null */
+	private static function tableless_json_valid_literal( string $sql ): ?array {
 		try {
 			$tokens = ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( rtrim( trim( $sql ), ';' ) );
 		} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
@@ -201,18 +223,7 @@ private function tableless_json_valid( string $sql ): ?WP_Markdown_Query_Result
 		if ( null !== $value && WP_Markdown_Native_SQL_Token::STRING !== $tokens[3]->type() ) {
 			return null;
 		}
-		$column = 'JSON_VALID(' . $tokens[3]->lexeme() . ')';
-		if ( null !== $value && $this->json_depth_exceeded_value( (string) $value ) ) {
-			return $this->mysql_json_depth_failure();
-		}
-		return WP_Markdown_Query_Result::selected(
-			array( array( $column => null === $value ? null : $this->json_valid( (string) $value ) ) ),
-			array( array( 'name' => $column, 'table' => '', 'type' => 3 ) )
-		);
-	}
-
-	public static function supports_tableless_scalar_projection( string $sql ): bool {
-		return ! ( ( new WP_Markdown_Native_Query_Parser() )->parse_tableless_scalar_projection( $sql ) instanceof WP_Markdown_Query_Result );
+		return array( 'value' => $value, 'column' => 'JSON_VALID(' . $tokens[3]->lexeme() . ')' );
 	}
 
 	private function tableless_scalar_type( WP_Markdown_Native_Query_Scalar_Expression $expression, int|string|null $value ): int {
diff --git a/inc/native/class-wp-markdown-native-schema-introspection.php b/inc/native/class-wp-markdown-native-schema-introspection.php
index 7c0ef83..3b1d879 100644
--- a/inc/native/class-wp-markdown-native-schema-introspection.php
+++ b/inc/native/class-wp-markdown-native-schema-introspection.php
@@ -390,6 +390,86 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 		}
 	}
 
+	/**
+	 * Discover the real tables needed to answer a bounded catalog request. This
+	 * intentionally recognizes only the literal TABLE_NAME predicates accepted
+	 * by the catalog executor; virtual catalog tables are never snapshotted.
+	 *
+	 * @return array<int,string>|null
+	 */
+	public static function requested_information_schema_tables( string $sql ): ?array {
+		try {
+			$tokens = ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( rtrim( trim( $sql ), ';' ) );
+		} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
+			return null;
+		}
+		$position = 0;
+		$word = static function ( string $expected ) use ( &$tokens, &$position ): bool {
+			if ( 0 !== strcasecmp( $expected, (string) ( $tokens[ $position ] ?? null )?->value() ) ) {
+				return false;
+			}
+			++$position;
+			return true;
+		};
+		$identifier = static function () use ( &$tokens, &$position ): ?string {
+			$token = $tokens[ $position ] ?? null;
+			if ( ! $token instanceof WP_Markdown_Native_SQL_Token || ! in_array( $token->type(), array( WP_Markdown_Native_SQL_Token::WORD, WP_Markdown_Native_SQL_Token::KEYWORD, WP_Markdown_Native_SQL_Token::QUOTED_IDENTIFIER ), true ) ) {
+				return null;
+			}
+			++$position;
+			return (string) $token->value();
+		};
+		if ( ! $word( 'SELECT' ) ) {
+			return null;
+		}
+		while ( ! $word( 'FROM' ) ) {
+			if ( WP_Markdown_Native_SQL_Token::END === ( $tokens[ $position ] ?? null )?->type() ) {
+				return null;
+			}
+			++$position;
+		}
+		if ( 0 !== strcasecmp( 'information_schema', (string) $identifier() ) || WP_Markdown_Native_SQL_Token::DOT !== ( $tokens[ $position ] ?? null )?->type() ) {
+			return null;
+		}
+		++$position;
+		$catalog = strtoupper( (string) $identifier() );
+		if ( ! in_array( $catalog, array( 'COLUMNS', 'TABLES' ), true ) || ! $word( 'WHERE' ) ) {
+			return null;
+		}
+		$tables = null;
+		do {
+			$column = strtoupper( (string) $identifier() );
+			if ( 'TABLE_NAME' !== $column ) {
+				while ( WP_Markdown_Native_SQL_Token::END !== ( $tokens[ $position ] ?? null )?->type() && 0 !== strcasecmp( 'AND', (string) ( $tokens[ $position ] ?? null )?->value() ) ) {
+					++$position;
+				}
+				continue;
+			}
+			$values = array();
+			if ( WP_Markdown_Native_SQL_Token::EQUALS === ( $tokens[ $position ] ?? null )?->type() ) {
+				++$position;
+				$token = $tokens[ $position++ ] ?? null;
+				if ( ! $token instanceof WP_Markdown_Native_SQL_Token || WP_Markdown_Native_SQL_Token::STRING !== $token->type() ) { return null; }
+				$values[] = (string) $token->value();
+			} elseif ( $word( 'IN' ) && WP_Markdown_Native_SQL_Token::LEFT_PAREN === ( $tokens[ $position ] ?? null )?->type() ) {
+				++$position;
+				do {
+					$token = $tokens[ $position++ ] ?? null;
+					if ( ! $token instanceof WP_Markdown_Native_SQL_Token || WP_Markdown_Native_SQL_Token::STRING !== $token->type() || count( $values ) >= self::MAX_INFORMATION_SCHEMA_VALUES ) { return null; }
+					$values[] = (string) $token->value();
+				} while ( WP_Markdown_Native_SQL_Token::COMMA === ( $tokens[ $position ] ?? null )?->type() && ++$position );
+				if ( WP_Markdown_Native_SQL_Token::RIGHT_PAREN !== ( $tokens[ $position ] ?? null )?->type() ) { return null; }
+				++$position;
+			} else {
+				return null;
+			}
+			$tables = null === $tables ? $values : array_values( array_intersect( $tables, $values ) );
+		} while ( $word( 'AND' ) );
+		return WP_Markdown_Native_SQL_Token::END === ( $tokens[ $position ] ?? null )?->type() && is_array( $tables ) && array() !== $tables
+			? array_values( array_unique( $tables ) )
+			: null;
+	}
+
 	/** @param array{columns:array<string,array<string,mixed>>,indexes:array<int,array<string,mixed>>} $definition @return array<int,array<string,int|string|null>> */
 	private function information_schema_columns( string $table, array $definition ): array {
 		$rows = array();
diff --git a/inc/native/class-wp-markdown-native-shadow-verifier.php b/inc/native/class-wp-markdown-native-shadow-verifier.php
index 52b4cbb..ca50a76 100644
--- a/inc/native/class-wp-markdown-native-shadow-verifier.php
+++ b/inc/native/class-wp-markdown-native-shadow-verifier.php
@@ -110,7 +110,10 @@ public function capture_input( string $query, object $database ): void {
 		} catch ( WP_Markdown_Native_Snapshot_Input_Exception $error ) {
 			// Input capture is observational and must never interrupt wpdb's query.
 			unset( $this->pending_inputs[ $key ] );
-			$this->pending_input_failures[ $key ] = $error->diagnostic();
+			$this->pending_input_failures[ $key ] = array(
+				'code'   => 'markdown_db_native_snapshot_input_unavailable',
+				'reason' => (string) ( $error->diagnostic()['reason'] ?? 'snapshot_capture_failed' ),
+			);
 		} catch ( Throwable $error ) {
 			unset( $this->pending_inputs[ $key ] );
 			$this->pending_input_failures[ $key ] = array( 'code' => 'markdown_db_native_snapshot_input_unavailable', 'reason' => 'snapshot_capture_failed' );
diff --git a/tests/smoke-native-shadow-sql-snapshot.php b/tests/smoke-native-shadow-sql-snapshot.php
index bd364b3..6b942a5 100644
--- a/tests/smoke-native-shadow-sql-snapshot.php
+++ b/tests/smoke-native-shadow-sql-snapshot.php
@@ -38,6 +38,8 @@ public function query( string $sql ): MDI_Snapshot_Result|false {
 			$result = new MDI_Snapshot_Result( array( array( 'Table' => $table, 'Create Table' => 'CREATE TABLE `' . $table . '` (`meta_id` bigint(20) unsigned NOT NULL, `site_id` bigint(20) unsigned NOT NULL, `meta_key` varchar(255) NOT NULL, `meta_value` longtext NOT NULL, PRIMARY KEY (`meta_id`))' ) ) );
 		} elseif ( 'SHOW CREATE TABLE `agents`' === $sql ) {
 			$result = new MDI_Snapshot_Result( array( array( 'Table' => 'agents', 'Create Table' => 'CREATE TABLE `agents` (`id` bigint(20) unsigned NOT NULL, `name` varchar(255) NOT NULL, PRIMARY KEY (`id`))' ) ) );
+		} elseif ( 'SHOW CREATE TABLE `wp_plugin_jobs`' === $sql ) {
+			$result = new MDI_Snapshot_Result( array( array( 'Table' => 'wp_plugin_jobs', 'Create Table' => 'CREATE TABLE `wp_plugin_jobs` (`id` bigint(20) unsigned NOT NULL, `status` varchar(64) NOT NULL, `payload` longtext NOT NULL, PRIMARY KEY (`id`))' ) ) );
 		} elseif ( 'SHOW CREATE TABLE `wp_2_options`' === $sql && $this->blog_table_absent ) {
 			$this->errno = 1146;
 			return false;
@@ -58,6 +60,9 @@ public function query( string $sql ): MDI_Snapshot_Result|false {
 		if ( 'SELECT * FROM `agents` LIMIT 10001' === $sql ) {
 			$result = new MDI_Snapshot_Result( $this->plugin_rows );
 		}
+		if ( 'SELECT * FROM `wp_plugin_jobs` LIMIT 10001' === $sql ) {
+			$result = new MDI_Snapshot_Result( array() );
+		}
 		if ( 'SELECT * FROM `wp_2_options` LIMIT 10001' === $sql ) {
 			$result = new MDI_Snapshot_Result( array( array( 'ID' => '1', 'option_value' => 'created' ) ) );
 		}
@@ -232,6 +237,24 @@ public function get_col_info( string $field ): array {
 $database->result_rows( array( array( 'one' => '1' ) ), array( array( 'name' => 'one', 'type' => 3 ) ) );
 $tableless->capture_input( 'SELECT 1 AS one', $database );
 $tableless->observe( 'SELECT 1 AS one', 1, $database );
+$json_tableless = new WP_Markdown_Native_Shadow_Verifier(
+	WP_Markdown_Native_Runtime_Factory::runtime( sys_get_temp_dir() ),
+	2,
+	array( 'input_mode' => 'sql_snapshot' )
+);
+$database->result_rows( array( array( 'JSON_VALID(\'{"valid":true}\')' => '1' ) ), array( array( 'name' => 'JSON_VALID(\'{"valid":true}\')', 'type' => 3 ) ) );
+$json_tableless->capture_input( "SELECT JSON_VALID('{\"valid\":true}')", $database );
+$json_tableless->observe( "SELECT JSON_VALID('{\"valid\":true}')", 1, $database );
+$database->result_rows( array( array( "JSON_VALID('{invalid}')" => '0' ) ), array( array( 'name' => "JSON_VALID('{invalid}')", 'type' => 3 ) ) );
+$json_tableless->capture_input( "SELECT JSON_VALID('{invalid}')", $database );
+$json_tableless->observe( "SELECT JSON_VALID('{invalid}')", 1, $database );
+$catalog_columns = WP_Markdown_Native_Authoritative_Snapshot_Runtime::capture(
+	$database,
+	"SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, IS_NULLABLE FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_plugin_jobs' AND COLUMN_NAME IN ('status', 'payload')",
+	'wp_'
+);
+$catalog_result = $catalog_columns->execute( new WP_Markdown_Query_Request( "SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, IS_NULLABLE FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_plugin_jobs' AND COLUMN_NAME IN ('status', 'payload')", 'wp_' ) );
+$catalog_engine = $catalog_columns->execute( new WP_Markdown_Query_Request( "SELECT ENGINE FROM information_schema.TABLES WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_plugin_jobs'", 'wp_' ) );
 $capture_count_at_bound = count( $database->source()->results );
 $bounded->capture_input( 'SELECT ID, post_title FROM wp_posts', $database );
 $bounded->observe( 'SELECT ID, post_title FROM wp_posts', 1, $database );
@@ -270,6 +293,13 @@ public function get_col_info( string $field ): array {
 	'tableless scalar SQL is independently compared through the stateless runtime path' => 1 === $tableless->report()['counts']['compatible']
 		&& 'native_runtime_fast_path' === ( $tableless->report()['context']['last_input_state']['read_connection'] ?? null )
 		&& array() === ( $tableless->report()['context']['last_input_state']['tables'] ?? null ),
+	'unaliased JSON_VALID uses the stateless capture path and independently executes both lifecycle literals' => 2 === $json_tableless->report()['counts']['compatible']
+		&& 0 === $json_tableless->report()['counts']['unsupported']
+		&& 'native_runtime_fast_path' === ( $json_tableless->report()['context']['last_input_state']['read_connection'] ?? null ),
+	'catalog capture snapshots requested physical DDL and independently executes COLUMNS metadata' => array( 'wp_plugin_jobs' ) === array_column( $catalog_columns->provenance()['tables'], 'table' )
+		&& array( 'status' => '64', 'payload' => '4294967295' ) === array_reduce( $catalog_result->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() ),
+	'catalog ENGINE remains an explicit unsupported projection after source discovery' => false === $catalog_engine->return_value()
+		&& 'unsupported_column' === ( $catalog_engine->diagnostic()['reason'] ?? null ),
 	'capture results are released after both schema and row reads' => array_reduce( $database->source()->results, static fn( bool $freed, MDI_Snapshot_Result $result ): bool => $freed && $result->freed, true ),
 );
 $failed = 0;

From bc71a840dd08a4d5204de9911154445ed37f5692 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 11:50:29 -0400
Subject: [PATCH 13/53] fix(shadow): retain snapshot capture evidence

---
 inc/native/class-wp-markdown-native-shadow-verifier.php | 4 +++-
 tests/run-mysql-shadow-corpus.php                       | 5 +----
 tests/smoke-native-shadow-sql-snapshot.php              | 1 +
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-shadow-verifier.php b/inc/native/class-wp-markdown-native-shadow-verifier.php
index ca50a76..17abec3 100644
--- a/inc/native/class-wp-markdown-native-shadow-verifier.php
+++ b/inc/native/class-wp-markdown-native-shadow-verifier.php
@@ -79,6 +79,7 @@ final class WP_Markdown_Native_Shadow_Verifier {
 	private array $pending_insert_ids = array();
 	/** @var array<string,array{code:string,reason:string}> */
 	private array $pending_input_failures = array();
+	private int $authoritative_snapshot_captures = 0;
 
 	public function __construct(
 		private WP_Markdown_Query_Runtime $runtime,
@@ -106,6 +107,7 @@ public function capture_input( string $query, object $database ): void {
 		}
 		try {
 			$this->pending_inputs[ $key ] = WP_Markdown_Native_Authoritative_Snapshot_Runtime::capture( $database, $query, $prefix );
+			++$this->authoritative_snapshot_captures;
 			unset( $this->pending_input_failures[ $key ] );
 		} catch ( WP_Markdown_Native_Snapshot_Input_Exception $error ) {
 			// Input capture is observational and must never interrupt wpdb's query.
@@ -242,7 +244,7 @@ public function report(): array {
 			'classifications'   => $this->classification_counts,
 			'first_blocker'    => $this->first_blocker,
 			'representatives'  => array_values( $this->representatives ),
-			'context'          => array_merge( $this->context, null === $this->first_query_context ? array() : array( 'first_query' => $this->first_query_context ), null === $this->last_input_state ? array() : array( 'last_input_state' => $this->last_input_state ) ),
+			'context'          => array_merge( $this->context, array( 'authoritative_snapshot_captures' => $this->authoritative_snapshot_captures ), null === $this->first_query_context ? array() : array( 'first_query' => $this->first_query_context ), null === $this->last_input_state ? array() : array( 'last_input_state' => $this->last_input_state ) ),
 		);
 	}
 
diff --git a/tests/run-mysql-shadow-corpus.php b/tests/run-mysql-shadow-corpus.php
index ca5dc57..8efca89 100644
--- a/tests/run-mysql-shadow-corpus.php
+++ b/tests/run-mysql-shadow-corpus.php
@@ -132,12 +132,9 @@
 	fwrite( STDERR, "Shadow report was absent or empty. Artifacts: {$root}\n" );
 	exit( 1 );
 }
-$input_tables = $shadow['context']['last_input_state']['tables'] ?? array();
 if ( 'sql_snapshot' !== ( $shadow['context']['input_mode'] ?? null )
 	|| (int) ( $shadow['counts']['compatible'] ?? 0 ) < 1
-	|| ! is_array( $input_tables )
-	|| array() === $input_tables
-	|| array_filter( $input_tables, static fn( mixed $table ): bool => ! is_array( $table ) || ! isset( $table['rows'], $table['sha256'], $table['schema_sha256'] ) )
+	|| (int) ( $shadow['context']['authoritative_snapshot_captures'] ?? 0 ) < 1
 ) {
 	fwrite( STDERR, "Shadow report did not prove a compatible sql_snapshot comparison. Artifacts: {$root}\n" );
 	exit( 1 );
diff --git a/tests/smoke-native-shadow-sql-snapshot.php b/tests/smoke-native-shadow-sql-snapshot.php
index 6b942a5..f0493d1 100644
--- a/tests/smoke-native-shadow-sql-snapshot.php
+++ b/tests/smoke-native-shadow-sql-snapshot.php
@@ -262,6 +262,7 @@ public function get_col_info( string $field ): array {
 $checks = array(
 	'authoritative snapshots compare with independently evaluated native SQL' => 2 === $second['counts']['compatible'] && 0 === $second['counts']['verifier_failures'],
 	'input provenance records bounded source rows without their values' => 'authoritative_mysql_connection_pre_query' === ( $first['context']['last_input_state']['read_connection'] ?? null )
+		&& 1 === ( $first['context']['authoritative_snapshot_captures'] ?? null )
 		&& 1 === ( $first['context']['last_input_state']['tables'][0]['rows'] ?? 0 )
 		&& 64 === strlen( (string) ( $first['context']['last_input_state']['tables'][0]['schema_sha256'] ?? '' ) )
 		&& 'pre_query_wpdb_insert_id' === ( $first['context']['last_input_state']['facade_state']['native_insert_id'] ?? null )

From 28ab0235487e7074f0e24ff96d2cce3a263ac1c0 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 11:55:59 -0400
Subject: [PATCH 14/53] test(shadow): retain redacted mismatch receipts

---
 ...ass-wp-markdown-native-shadow-verifier.php | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/inc/native/class-wp-markdown-native-shadow-verifier.php b/inc/native/class-wp-markdown-native-shadow-verifier.php
index 17abec3..dd8cfab 100644
--- a/inc/native/class-wp-markdown-native-shadow-verifier.php
+++ b/inc/native/class-wp-markdown-native-shadow-verifier.php
@@ -222,6 +222,7 @@ public function observe( string $query, mixed $return_value, object $database ):
 				array(
 					'mismatch_paths'     => $paths,
 					'mismatches_truncated' => count( $comparison['mismatches'] ) > count( $paths ),
+					'comparison_receipt' => $this->comparison_receipt( $expected, $actual ),
 				)
 			);
 		} catch ( Throwable $error ) {
@@ -339,6 +340,26 @@ private function safe_reason( string $reason ): string {
 		return '' === $reason ? 'unknown' : substr( $reason, 0, 128 );
 	}
 
+	/** Retain field descriptors and opaque row receipts without publishing query values. */
+	private function comparison_receipt( array $expected, array $actual ): array {
+		$columns = static fn( array $result ): array => array_map(
+			static fn( array $column ): array => array(
+				'name' => (string) ( $column['name'] ?? '' ),
+				'type' => null === ( $column['type'] ?? null ) ? null : (string) $column['type'],
+			),
+			is_array( $result['columns'] ?? null ) ? $result['columns'] : array()
+		);
+		$rows = static fn( array $result ): array => is_array( $result['rows'] ?? null ) ? $result['rows'] : array();
+		$expected_rows = $rows( $expected );
+		$actual_rows = $rows( $actual );
+		return array(
+			'expected_columns' => $columns( $expected ),
+			'actual_columns'   => $columns( $actual ),
+			'expected_rows'    => array( 'count' => count( $expected_rows ), 'sha256' => hash( 'sha256', serialize( $expected_rows ) ) ),
+			'actual_rows'      => array( 'count' => count( $actual_rows ), 'sha256' => hash( 'sha256', serialize( $actual_rows ) ) ),
+		);
+	}
+
 	/** Compare all caller-visible error state except server-specific error text. */
 	private function has_matching_missing_table_error_state( array $expected, array $actual ): bool {
 		if ( false !== ( $expected['return']['value'] ?? null ) || 1146 !== (int) ( $expected['error_code'] ?? 0 ) ) {

From c316a467230f063c73eb16a87ec2dc1288b97b4c Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 12:02:17 -0400
Subject: [PATCH 15/53] fix(native): match MySQL field descriptors

---
 inc/native/class-wp-markdown-native-query-executor.php      | 4 ++--
 .../class-wp-markdown-native-schema-introspection.php       | 6 +++++-
 tests/smoke-native-plugin-schema-query.php                  | 2 +-
 tests/smoke-native-scalar-clauses.php                       | 2 +-
 tests/smoke-native-shadow-sql-snapshot.php                  | 5 +++--
 5 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 1bec5f7..13c4b80 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -193,7 +193,7 @@ private function tableless_json_valid( string $sql ): ?WP_Markdown_Query_Result
 		}
 		return WP_Markdown_Query_Result::selected(
 			array( array( $column => null === $value ? null : $this->json_valid( (string) $value ) ) ),
-			array( array( 'name' => $column, 'table' => '', 'type' => 3 ) )
+			array( array( 'name' => $column, 'table' => '', 'type' => 8 ) )
 		);
 	}
 
@@ -229,7 +229,7 @@ private static function tableless_json_valid_literal( string $sql ): ?array {
 	private function tableless_scalar_type( WP_Markdown_Native_Query_Scalar_Expression $expression, int|string|null $value ): int {
 		if ( null === $value ) { return 6; }
 		if ( 'literal' === $expression->kind() ) { return is_int( $value ) ? 3 : ( is_numeric( $value ) ? 246 : 253 ); }
-		return 'JSON_VALID' === $expression->kind() ? 3 : 253;
+		return 'JSON_VALID' === $expression->kind() ? 8 : 253;
 	}
 
 	/** Release this logical connection's root-scoped advisory locks. */
diff --git a/inc/native/class-wp-markdown-native-schema-introspection.php b/inc/native/class-wp-markdown-native-schema-introspection.php
index 3b1d879..90d893f 100644
--- a/inc/native/class-wp-markdown-native-schema-introspection.php
+++ b/inc/native/class-wp-markdown-native-schema-introspection.php
@@ -517,7 +517,11 @@ private function information_schema_metadata( array $projection, string $catalog
 			static fn( array $column ): array => array(
 				'name' => $column['alias'],
 				'table' => $catalog,
-				'type' => in_array( $column['name'], array( 'ORDINAL_POSITION', 'CHARACTER_MAXIMUM_LENGTH' ), true ) ? 8 : 253,
+				'type' => match ( $column['name'] ) {
+					'ORDINAL_POSITION', 'CHARACTER_MAXIMUM_LENGTH' => 8,
+					'DATA_TYPE' => 251,
+					default => 253,
+				},
 			),
 			$projection
 		);
diff --git a/tests/smoke-native-plugin-schema-query.php b/tests/smoke-native-plugin-schema-query.php
index ad1be2b..70ac668 100644
--- a/tests/smoke-native-plugin-schema-query.php
+++ b/tests/smoke-native-plugin-schema-query.php
@@ -175,7 +175,7 @@ function mdi_plugin_schema_remove_tree( string $root ): void {
 		&& 'PRI' === ( $information_columns->wpdb_state()['last_result'][0]->COLUMN_KEY ?? null )
 		&& '32' === ( $information_columns->wpdb_state()['last_result'][2]->CHARACTER_MAXIMUM_LENGTH ?? null )
 		&& null === ( $information_columns->wpdb_state()['last_result'][0]->CHARACTER_MAXIMUM_LENGTH ?? null )
-		&& array( 253, 253, 8, 8, 253, 253, 253, 253, 253, 253 ) === array_map( static fn( object $column ): int => $column->type, $information_columns->wpdb_state()['col_info'] ),
+		&& array( 253, 253, 8, 8, 253, 253, 251, 253, 253, 253 ) === array_map( static fn( object $column ): int => $column->type, $information_columns->wpdb_state()['col_info'] ),
 	'information_schema predicates preserve schema equality and AND intersections' => 0 === $absent_information_schema->return_value()
 		&& 0 === $contradictory_information_tables->return_value()
 		&& 0 === $contradictory_information_columns->return_value(),
diff --git a/tests/smoke-native-scalar-clauses.php b/tests/smoke-native-scalar-clauses.php
index a69f8f9..baca993 100644
--- a/tests/smoke-native-scalar-clauses.php
+++ b/tests/smoke-native-scalar-clauses.php
@@ -74,7 +74,7 @@
 		&& '0' === ( $json_invalid->wpdb_state()['last_result'][0]->{'JSON_VALID(\'{broken}\')'} ?? null )
 		&& null === ( $json_null->wpdb_state()['last_result'][0]->{'JSON_VALID(NULL)'} ?? null )
 		&& 'JSON_VALID(\'{"event":true}\')' === ( $json_valid->wpdb_state()['col_info'][0]->name ?? null )
-		&& 3 === ( $json_valid->wpdb_state()['col_info'][0]->type ?? null )
+		&& 8 === ( $json_valid->wpdb_state()['col_info'][0]->type ?? null )
 		&& '1' === ( $json_alias->wpdb_state()['last_result'][0]->valid_json ?? null )
 		&& '1' === ( $json_array_depth_100->wpdb_state()['last_result'][0]->valid_json ?? null )
 		&& 3157 === ( $json_array_depth_101->wpdb_state()['last_errno'] ?? null )
diff --git a/tests/smoke-native-shadow-sql-snapshot.php b/tests/smoke-native-shadow-sql-snapshot.php
index f0493d1..a9e79c0 100644
--- a/tests/smoke-native-shadow-sql-snapshot.php
+++ b/tests/smoke-native-shadow-sql-snapshot.php
@@ -242,10 +242,10 @@ public function get_col_info( string $field ): array {
 	2,
 	array( 'input_mode' => 'sql_snapshot' )
 );
-$database->result_rows( array( array( 'JSON_VALID(\'{"valid":true}\')' => '1' ) ), array( array( 'name' => 'JSON_VALID(\'{"valid":true}\')', 'type' => 3 ) ) );
+$database->result_rows( array( array( 'JSON_VALID(\'{"valid":true}\')' => '1' ) ), array( array( 'name' => 'JSON_VALID(\'{"valid":true}\')', 'type' => 8 ) ) );
 $json_tableless->capture_input( "SELECT JSON_VALID('{\"valid\":true}')", $database );
 $json_tableless->observe( "SELECT JSON_VALID('{\"valid\":true}')", 1, $database );
-$database->result_rows( array( array( "JSON_VALID('{invalid}')" => '0' ) ), array( array( 'name' => "JSON_VALID('{invalid}')", 'type' => 3 ) ) );
+$database->result_rows( array( array( "JSON_VALID('{invalid}')" => '0' ) ), array( array( 'name' => "JSON_VALID('{invalid}')", 'type' => 8 ) ) );
 $json_tableless->capture_input( "SELECT JSON_VALID('{invalid}')", $database );
 $json_tableless->observe( "SELECT JSON_VALID('{invalid}')", 1, $database );
 $catalog_columns = WP_Markdown_Native_Authoritative_Snapshot_Runtime::capture(
@@ -298,6 +298,7 @@ public function get_col_info( string $field ): array {
 		&& 0 === $json_tableless->report()['counts']['unsupported']
 		&& 'native_runtime_fast_path' === ( $json_tableless->report()['context']['last_input_state']['read_connection'] ?? null ),
 	'catalog capture snapshots requested physical DDL and independently executes COLUMNS metadata' => array( 'wp_plugin_jobs' ) === array_column( $catalog_columns->provenance()['tables'], 'table' )
+		&& 251 === ( $catalog_result->wpdb_state()['col_info'][1]->type ?? null )
 		&& array( 'status' => '64', 'payload' => '4294967295' ) === array_reduce( $catalog_result->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() ),
 	'catalog ENGINE remains an explicit unsupported projection after source discovery' => false === $catalog_engine->return_value()
 		&& 'unsupported_column' === ( $catalog_engine->diagnostic()['reason'] ?? null ),

From 086d08d07f660f0d6a6a10f62065f8ca6b42026c Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 12:06:06 -0400
Subject: [PATCH 16/53] fix(shadow): bind authoritative catalog schema

---
 ...wn-native-authoritative-snapshot-runtime.php |  9 ++++++++-
 .../class-wp-markdown-native-query-executor.php |  9 ++++++---
 ...-wp-markdown-native-schema-introspection.php | 17 +++++++++++------
 3 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
index 1851c7b..19b5851 100644
--- a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
+++ b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
@@ -27,6 +27,7 @@ public static function capture( object $database, string $sql, string $prefix ):
 		}
 
 		$prefixes = self::schema_prefixes( $database, $prefix );
+		$database_name = self::database_name( $connection );
 		$registry = new WP_Markdown_Native_Table_Registry();
 		$provenance = array();
 		foreach ( $tables as $table ) {
@@ -48,7 +49,7 @@ public static function capture( object $database, string $sql, string $prefix ):
 			$registry->register( $table, $schema, new WP_Markdown_Native_Authoritative_Snapshot_Provider( $rows, $schema ) );
 			$provenance[] = array( 'table' => $table, 'exists' => true, 'rows' => count( $rows ), 'sha256' => hash( 'sha256', self::encode_rows( $rows ) ), 'schema_sha256' => hash( 'sha256', $definition ) );
 		}
-		return new self( new WP_Markdown_Native_Query_Runtime( $registry ), $provenance );
+		return new self( new WP_Markdown_Native_Query_Runtime( $registry, database_name: $database_name ), $provenance );
 	}
 
 	private static function trace_runtime_phase( string $phase, ?string $sql = null ): void {
@@ -78,6 +79,12 @@ private static function schema_prefixes( object $database, string $prefix ): arr
 		return array_values( array_unique( array_filter( $prefixes, static fn( string $candidate ): bool => '' !== $candidate ) ) );
 	}
 
+	private static function database_name( object $connection ): ?string {
+		$row = self::one_row( $connection, 'SELECT DATABASE()' );
+		$value = is_array( $row ) ? reset( $row ) : null;
+		return is_string( $value ) ? $value : null;
+	}
+
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
 		$result = $this->runtime->execute( $request );
 		$diagnostic = $result->diagnostic() ?? array();
diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 13c4b80..94e6936 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -43,6 +43,7 @@ final class WP_Markdown_Native_Query_Runtime implements WP_Markdown_Query_Runtim
 	/** @var array<string,array{seed1:int,seed2:int}> */
 	private array $rand_states = array();
 	private WP_Markdown_Native_Schema_Introspection $schema_introspection;
+	private ?string $database_name;
 
 	public function __construct(
 		private WP_Markdown_Native_Table_Registry $registry,
@@ -53,9 +54,11 @@ public function __construct(
 		private ?WP_Markdown_Native_Transaction_Journal $transactions = null,
 		private ?WP_Markdown_Native_Post_Mutation_Runtime $post_mutations = null,
 		private int $correlated_subquery_limit = self::MAX_CORRELATED_SUBQUERY_EVALUATIONS,
-		private ?WP_Markdown_Native_Advisory_Locks $advisory_locks = null
+		private ?WP_Markdown_Native_Advisory_Locks $advisory_locks = null,
+		?string $database_name = null
 	) {
-		$this->schema_introspection = new WP_Markdown_Native_Schema_Introspection( $registry );
+		$this->database_name = $database_name;
+		$this->schema_introspection = new WP_Markdown_Native_Schema_Introspection( $registry, database_name: $database_name );
 	}
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
@@ -86,7 +89,7 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		// The canonical store is a directory, not a named server database.
 		if ( 1 === preg_match( '/^\s*SELECT\s+DATABASE\s*\(\s*\)\s*;?\s*$/i', $request->sql() ) ) {
 			return WP_Markdown_Query_Result::selected(
-				array( array( 'DATABASE()' => defined( 'DB_NAME' ) ? (string) DB_NAME : '' ) ),
+				array( array( 'DATABASE()' => $this->database_name ?? ( defined( 'DB_NAME' ) ? (string) DB_NAME : '' ) ) ),
 				array( array( 'name' => 'DATABASE()', 'table' => '', 'type' => 253 ) )
 			);
 		}
diff --git a/inc/native/class-wp-markdown-native-schema-introspection.php b/inc/native/class-wp-markdown-native-schema-introspection.php
index 90d893f..fada374 100644
--- a/inc/native/class-wp-markdown-native-schema-introspection.php
+++ b/inc/native/class-wp-markdown-native-schema-introspection.php
@@ -229,7 +229,8 @@ final class WP_Markdown_Native_Schema_Introspection {
 	private const MAX_INFORMATION_SCHEMA_ROWS = 1000;
 	public function __construct(
 		private readonly WP_Markdown_Native_Table_Registry $registry,
-		private readonly WP_Markdown_Native_Schema_Introspection_Parser $parser = new WP_Markdown_Native_Schema_Introspection_Parser()
+		private readonly WP_Markdown_Native_Schema_Introspection_Parser $parser = new WP_Markdown_Native_Schema_Introspection_Parser(),
+		private readonly ?string $database_name = null
 	) {}
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
@@ -321,7 +322,7 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 				if ( 'TABLE_SCHEMA' === $column && WP_Markdown_Native_SQL_Token::EQUALS === ( $tokens[ $position ] ?? null )?->type() ) {
 					++$position;
 					if ( $word( 'DATABASE' ) && WP_Markdown_Native_SQL_Token::LEFT_PAREN === ( $tokens[ $position ] ?? null )?->type() && WP_Markdown_Native_SQL_Token::RIGHT_PAREN === ( $tokens[ $position + 1 ] ?? null )?->type() ) {
-						$values[] = defined( 'DB_NAME' ) ? (string) DB_NAME : '';
+						$values[] = $this->database_name();
 						$position += 2;
 					} elseif ( WP_Markdown_Native_SQL_Token::STRING === ( $tokens[ $position ] ?? null )?->type() ) {
 						$values[] = (string) $tokens[ $position++ ]->value();
@@ -356,7 +357,7 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 			if ( ! isset( $predicates['TABLE_SCHEMA'], $predicates['TABLE_NAME'] ) || WP_Markdown_Native_SQL_Token::END !== ( $tokens[ $position ] ?? null )?->type() ) {
 				return $this->failure( 'unsupported_lookup', 'mdi-native requires a bounded information_schema table lookup.' );
 			}
-			$schema = defined( 'DB_NAME' ) ? (string) DB_NAME : '';
+			$schema = $this->database_name();
 			if ( ! in_array( $schema, $predicates['TABLE_SCHEMA'], true ) || array() === $predicates['TABLE_NAME'] ) {
 				return WP_Markdown_Query_Result::selected( array(), $this->information_schema_metadata( $projection, $catalog ) );
 			}
@@ -475,7 +476,7 @@ private function information_schema_columns( string $table, array $definition ):
 		$rows = array();
 		foreach ( $definition['columns'] as $position => $column ) {
 			$rows[] = array(
-				'TABLE_SCHEMA' => defined( 'DB_NAME' ) ? (string) DB_NAME : '',
+				'TABLE_SCHEMA' => $this->database_name(),
 				'TABLE_NAME' => $table,
 				'COLUMN_NAME' => $position,
 				'ORDINAL_POSITION' => (string) ( count( $rows ) + 1 ),
@@ -493,7 +494,7 @@ private function information_schema_columns( string $table, array $definition ):
 
 	/** @return array<string,string> */
 	private function information_schema_table( string $table ): array {
-		return array( 'TABLE_SCHEMA' => defined( 'DB_NAME' ) ? (string) DB_NAME : '', 'TABLE_NAME' => $table, 'TABLE_TYPE' => 'BASE TABLE' );
+		return array( 'TABLE_SCHEMA' => $this->database_name(), 'TABLE_NAME' => $table, 'TABLE_TYPE' => 'BASE TABLE' );
 	}
 
 	/** @param array<string,mixed> $column */
@@ -567,7 +568,7 @@ private function server_values( string $operation, ?string $pattern, array $name
 
 	private function tables( ?string $pattern ): WP_Markdown_Query_Result {
 		$rows = array();
-		$column = 'Tables_in_' . ( defined( 'DB_NAME' ) ? (string) DB_NAME : '' );
+		$column = 'Tables_in_' . $this->database_name();
 		foreach ( $this->registry->table_names() as $table ) {
 			if ( null === $pattern || $this->matches( $table, $pattern ) ) {
 				$rows[] = array( $column => $table );
@@ -701,4 +702,8 @@ private function failure( string $reason, string $message ): WP_Markdown_Query_R
 			)
 		);
 	}
+
+	private function database_name(): string {
+		return $this->database_name ?? ( defined( 'DB_NAME' ) ? (string) DB_NAME : '' );
+	}
 }

From 577b4d97314b54d5bdab4875b2ebe73c954194b0 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 12:08:51 -0400
Subject: [PATCH 17/53] test(shadow): retain catalog schema receipts

---
 ...class-wp-markdown-native-shadow-verifier.php | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/inc/native/class-wp-markdown-native-shadow-verifier.php b/inc/native/class-wp-markdown-native-shadow-verifier.php
index dd8cfab..c3a0c5f 100644
--- a/inc/native/class-wp-markdown-native-shadow-verifier.php
+++ b/inc/native/class-wp-markdown-native-shadow-verifier.php
@@ -357,9 +357,26 @@ private function comparison_receipt( array $expected, array $actual ): array {
 			'actual_columns'   => $columns( $actual ),
 			'expected_rows'    => array( 'count' => count( $expected_rows ), 'sha256' => hash( 'sha256', serialize( $expected_rows ) ) ),
 			'actual_rows'      => array( 'count' => count( $actual_rows ), 'sha256' => hash( 'sha256', serialize( $actual_rows ) ) ),
+			'catalog_schema_rows' => $this->catalog_schema_rows( $expected_rows, $actual_rows ),
 		);
 	}
 
+	/** Retain only public schema facts when a catalog response differs. */
+	private function catalog_schema_rows( array $expected, array $actual ): ?array {
+		$keys = array( 'COLUMN_NAME', 'DATA_TYPE', 'CHARACTER_MAXIMUM_LENGTH', 'IS_NULLABLE' );
+		$sanitize = static function ( array $rows ) use ( $keys ): ?array {
+			foreach ( $rows as $row ) {
+				if ( ! is_array( $row ) || array_diff( array_keys( $row ), $keys ) !== array() ) {
+					return null;
+				}
+			}
+			return array_map( static fn( array $row ): array => array_intersect_key( $row, array_flip( $keys ) ), $rows );
+		};
+		$expected = $sanitize( $expected );
+		$actual = $sanitize( $actual );
+		return null === $expected || null === $actual ? null : array( 'expected' => $expected, 'actual' => $actual );
+	}
+
 	/** Compare all caller-visible error state except server-specific error text. */
 	private function has_matching_missing_table_error_state( array $expected, array $actual ): bool {
 		if ( false !== ( $expected['return']['value'] ?? null ) || 1146 !== (int) ( $expected['error_code'] ?? 0 ) ) {

From f6dbd61d0b1cad7ad6d4b7abea50f1a631845fd4 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 12:18:45 -0400
Subject: [PATCH 18/53] test(shadow): retain snapshot provenance

---
 ...-wp-markdown-native-authoritative-snapshot-runtime.php | 8 ++++----
 inc/native/class-wp-markdown-native-shadow-verifier.php   | 1 +
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
index 19b5851..03a8438 100644
--- a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
+++ b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
@@ -11,7 +11,7 @@ final class WP_Markdown_Native_Authoritative_Snapshot_Runtime implements WP_Mark
 	private const MAX_BYTES_PER_TABLE = 8388608;
 
 	/** @param array<int,array{table:string,exists:bool,rows?:int,sha256?:string,schema_sha256?:string}> $provenance */
-	public function __construct( private WP_Markdown_Query_Runtime $runtime, private array $provenance ) {}
+	public function __construct( private WP_Markdown_Query_Runtime $runtime, private array $provenance, private ?string $database_name = null ) {}
 
 	public static function capture( object $database, string $sql, string $prefix ): self {
 		self::trace_runtime_phase( 'capture', $sql );
@@ -49,7 +49,7 @@ public static function capture( object $database, string $sql, string $prefix ):
 			$registry->register( $table, $schema, new WP_Markdown_Native_Authoritative_Snapshot_Provider( $rows, $schema ) );
 			$provenance[] = array( 'table' => $table, 'exists' => true, 'rows' => count( $rows ), 'sha256' => hash( 'sha256', self::encode_rows( $rows ) ), 'schema_sha256' => hash( 'sha256', $definition ) );
 		}
-		return new self( new WP_Markdown_Native_Query_Runtime( $registry, database_name: $database_name ), $provenance );
+		return new self( new WP_Markdown_Native_Query_Runtime( $registry, database_name: $database_name ), $provenance, $database_name );
 	}
 
 	private static function trace_runtime_phase( string $phase, ?string $sql = null ): void {
@@ -111,9 +111,9 @@ private function has_explicitly_absent_source( string $sql ): bool {
 		return array() !== array_intersect( self::tables_in( $sql ), $absent );
 	}
 
-	/** @return array{read_connection:string,tables:array<int,array{table:string,exists:bool,rows?:int,sha256?:string,schema_sha256?:string}>} */
+	/** @return array{read_connection:string,database_sha256:?string,tables:array<int,array{table:string,exists:bool,rows?:int,sha256?:string,schema_sha256?:string}>} */
 	public function provenance(): array {
-		return array( 'read_connection' => 'authoritative_mysql_connection_pre_query', 'tables' => $this->provenance );
+		return array( 'read_connection' => 'authoritative_mysql_connection_pre_query', 'database_sha256' => null === $this->database_name ? null : hash( 'sha256', $this->database_name ), 'tables' => $this->provenance );
 	}
 
 	/** @return array<int,string> */
diff --git a/inc/native/class-wp-markdown-native-shadow-verifier.php b/inc/native/class-wp-markdown-native-shadow-verifier.php
index c3a0c5f..7cb1f7c 100644
--- a/inc/native/class-wp-markdown-native-shadow-verifier.php
+++ b/inc/native/class-wp-markdown-native-shadow-verifier.php
@@ -223,6 +223,7 @@ public function observe( string $query, mixed $return_value, object $database ):
 					'mismatch_paths'     => $paths,
 					'mismatches_truncated' => count( $comparison['mismatches'] ) > count( $paths ),
 					'comparison_receipt' => $this->comparison_receipt( $expected, $actual ),
+					'input_provenance' => $provenance ?? array(),
 				)
 			);
 		} catch ( Throwable $error ) {

From f39abfa46e9f86c60eeaac4be4a6e57bf56688d8 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 12:22:48 -0400
Subject: [PATCH 19/53] fix(native): match catalog column ordering

---
 inc/native/class-wp-markdown-native-schema-introspection.php | 3 +++
 tests/smoke-native-plugin-schema-query.php                   | 2 +-
 tests/smoke-native-shadow-sql-snapshot.php                   | 2 +-
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-schema-introspection.php b/inc/native/class-wp-markdown-native-schema-introspection.php
index fada374..3744b33 100644
--- a/inc/native/class-wp-markdown-native-schema-introspection.php
+++ b/inc/native/class-wp-markdown-native-schema-introspection.php
@@ -385,6 +385,9 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 					$rows[] = $row;
 				}
 			}
+			if ( 'COLUMNS' === $catalog && 1 === count( $predicates['TABLE_NAME'] ) && in_array( 'COLUMN_NAME', array_column( $projection, 'name' ), true ) ) {
+				usort( $rows, static fn( array $left, array $right ): int => strcmp( (string) ( $left['COLUMN_NAME'] ?? '' ), (string) ( $right['COLUMN_NAME'] ?? '' ) ) );
+			}
 			return WP_Markdown_Query_Result::selected( $rows, $this->information_schema_metadata( $projection, $catalog ) );
 		} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
 			return null;
diff --git a/tests/smoke-native-plugin-schema-query.php b/tests/smoke-native-plugin-schema-query.php
index 70ac668..b3ea409 100644
--- a/tests/smoke-native-plugin-schema-query.php
+++ b/tests/smoke-native-plugin-schema-query.php
@@ -183,7 +183,7 @@ function mdi_plugin_schema_remove_tree( string $root ): void {
 		&& 'unsupported_column' === ( $information_engine->diagnostic()['reason'] ?? null ),
 	'information_schema catalog scans remain fail-closed without a bounded table name' => false === $unbounded_information->return_value()
 		&& 'unsupported_lookup' === ( $unbounded_information->diagnostic()['reason'] ?? null ),
-	'information_schema reports TEXT character maxima and bounds list cardinality' => array( 'task_url' => '65535', 'payload' => '4294967295' ) === array_reduce( $text_information->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() )
+	'information_schema reports TEXT character maxima and bounds list cardinality' => array( 'payload' => '4294967295', 'task_url' => '65535' ) === array_reduce( $text_information->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() )
 		&& false === $overwide_information->return_value()
 		&& 'resource_limit' === ( $overwide_information->diagnostic()['reason'] ?? null ),
 	'finite result limits do not authorize unbounded residual source scans' => false === $limited_residual->return_value()
diff --git a/tests/smoke-native-shadow-sql-snapshot.php b/tests/smoke-native-shadow-sql-snapshot.php
index a9e79c0..29c4fee 100644
--- a/tests/smoke-native-shadow-sql-snapshot.php
+++ b/tests/smoke-native-shadow-sql-snapshot.php
@@ -299,7 +299,7 @@ public function get_col_info( string $field ): array {
 		&& 'native_runtime_fast_path' === ( $json_tableless->report()['context']['last_input_state']['read_connection'] ?? null ),
 	'catalog capture snapshots requested physical DDL and independently executes COLUMNS metadata' => array( 'wp_plugin_jobs' ) === array_column( $catalog_columns->provenance()['tables'], 'table' )
 		&& 251 === ( $catalog_result->wpdb_state()['col_info'][1]->type ?? null )
-		&& array( 'status' => '64', 'payload' => '4294967295' ) === array_reduce( $catalog_result->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() ),
+		&& array( 'payload' => '4294967295', 'status' => '64' ) === array_reduce( $catalog_result->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() ),
 	'catalog ENGINE remains an explicit unsupported projection after source discovery' => false === $catalog_engine->return_value()
 		&& 'unsupported_column' === ( $catalog_engine->diagnostic()['reason'] ?? null ),
 	'capture results are released after both schema and row reads' => array_reduce( $database->source()->results, static fn( bool $freed, MDI_Snapshot_Result $result ): bool => $freed && $result->freed, true ),

From 8cf423c70816b345c498cc03274534d90f851640 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 12:25:25 -0400
Subject: [PATCH 20/53] fix(shadow): compare unordered catalog rows as bags

---
 ...p-markdown-native-schema-introspection.php | 21 ++++++++++++++++---
 ...ass-wp-markdown-native-shadow-verifier.php |  2 +-
 tests/smoke-native-plugin-schema-query.php    |  2 +-
 tests/smoke-native-shadow-sql-snapshot.php    |  2 +-
 4 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-schema-introspection.php b/inc/native/class-wp-markdown-native-schema-introspection.php
index 3744b33..0230c4e 100644
--- a/inc/native/class-wp-markdown-native-schema-introspection.php
+++ b/inc/native/class-wp-markdown-native-schema-introspection.php
@@ -385,9 +385,6 @@ public function select_information_schema( WP_Markdown_Query_Request $request ):
 					$rows[] = $row;
 				}
 			}
-			if ( 'COLUMNS' === $catalog && 1 === count( $predicates['TABLE_NAME'] ) && in_array( 'COLUMN_NAME', array_column( $projection, 'name' ), true ) ) {
-				usort( $rows, static fn( array $left, array $right ): int => strcmp( (string) ( $left['COLUMN_NAME'] ?? '' ), (string) ( $right['COLUMN_NAME'] ?? '' ) ) );
-			}
 			return WP_Markdown_Query_Result::selected( $rows, $this->information_schema_metadata( $projection, $catalog ) );
 		} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
 			return null;
@@ -474,6 +471,24 @@ public static function requested_information_schema_tables( string $sql ): ?arra
 			: null;
 	}
 
+	/** Catalog reads without an ORDER BY or LIMIT have relationally unordered rows. */
+	public static function is_unordered_unbounded_catalog_read( string $sql ): bool {
+		if ( null === self::requested_information_schema_tables( $sql ) ) {
+			return false;
+		}
+		try {
+			$tokens = ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( rtrim( trim( $sql ), ';' ) );
+		} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
+			return false;
+		}
+		foreach ( $tokens as $token ) {
+			if ( in_array( strtoupper( (string) $token->value() ), array( 'ORDER', 'LIMIT' ), true ) ) {
+				return false;
+			}
+		}
+		return true;
+	}
+
 	/** @param array{columns:array<string,array<string,mixed>>,indexes:array<int,array<string,mixed>>} $definition @return array<int,array<string,int|string|null>> */
 	private function information_schema_columns( string $table, array $definition ): array {
 		$rows = array();
diff --git a/inc/native/class-wp-markdown-native-shadow-verifier.php b/inc/native/class-wp-markdown-native-shadow-verifier.php
index 7cb1f7c..9d6a24c 100644
--- a/inc/native/class-wp-markdown-native-shadow-verifier.php
+++ b/inc/native/class-wp-markdown-native-shadow-verifier.php
@@ -202,7 +202,7 @@ public function observe( string $query, mixed $return_value, object $database ):
 				$expected,
 				$actual
 			);
-			if ( ! $comparison['compatible'] && $this->has_unordered_unbounded_result( $query ) ) {
+			if ( ! $comparison['compatible'] && ( $this->has_unordered_unbounded_result( $query ) || WP_Markdown_Native_Schema_Introspection::is_unordered_unbounded_catalog_read( $query ) ) ) {
 				$comparison = WP_Markdown_Query_Compatibility_Comparator::compare( $this->rows_as_bag( $expected ), $this->rows_as_bag( $actual ) );
 			}
 			if ( $comparison['compatible'] ) {
diff --git a/tests/smoke-native-plugin-schema-query.php b/tests/smoke-native-plugin-schema-query.php
index b3ea409..70ac668 100644
--- a/tests/smoke-native-plugin-schema-query.php
+++ b/tests/smoke-native-plugin-schema-query.php
@@ -183,7 +183,7 @@ function mdi_plugin_schema_remove_tree( string $root ): void {
 		&& 'unsupported_column' === ( $information_engine->diagnostic()['reason'] ?? null ),
 	'information_schema catalog scans remain fail-closed without a bounded table name' => false === $unbounded_information->return_value()
 		&& 'unsupported_lookup' === ( $unbounded_information->diagnostic()['reason'] ?? null ),
-	'information_schema reports TEXT character maxima and bounds list cardinality' => array( 'payload' => '4294967295', 'task_url' => '65535' ) === array_reduce( $text_information->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() )
+	'information_schema reports TEXT character maxima and bounds list cardinality' => array( 'task_url' => '65535', 'payload' => '4294967295' ) === array_reduce( $text_information->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() )
 		&& false === $overwide_information->return_value()
 		&& 'resource_limit' === ( $overwide_information->diagnostic()['reason'] ?? null ),
 	'finite result limits do not authorize unbounded residual source scans' => false === $limited_residual->return_value()
diff --git a/tests/smoke-native-shadow-sql-snapshot.php b/tests/smoke-native-shadow-sql-snapshot.php
index 29c4fee..a9e79c0 100644
--- a/tests/smoke-native-shadow-sql-snapshot.php
+++ b/tests/smoke-native-shadow-sql-snapshot.php
@@ -299,7 +299,7 @@ public function get_col_info( string $field ): array {
 		&& 'native_runtime_fast_path' === ( $json_tableless->report()['context']['last_input_state']['read_connection'] ?? null ),
 	'catalog capture snapshots requested physical DDL and independently executes COLUMNS metadata' => array( 'wp_plugin_jobs' ) === array_column( $catalog_columns->provenance()['tables'], 'table' )
 		&& 251 === ( $catalog_result->wpdb_state()['col_info'][1]->type ?? null )
-		&& array( 'payload' => '4294967295', 'status' => '64' ) === array_reduce( $catalog_result->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() ),
+		&& array( 'status' => '64', 'payload' => '4294967295' ) === array_reduce( $catalog_result->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() ),
 	'catalog ENGINE remains an explicit unsupported projection after source discovery' => false === $catalog_engine->return_value()
 		&& 'unsupported_column' === ( $catalog_engine->diagnostic()['reason'] ?? null ),
 	'capture results are released after both schema and row reads' => array_reduce( $database->source()->results, static fn( bool $freed, MDI_Snapshot_Result $result ): bool => $freed && $result->freed, true ),

From 3d946ef69b005594f212193ba4ff02ca9e08fdcb Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 12:31:34 -0400
Subject: [PATCH 21/53] test(shadow): retain catalog lifecycle receipt

---
 ...-native-authoritative-snapshot-runtime.php | 28 +++++++++++++++++--
 tests/smoke-native-shadow-sql-snapshot.php    |  7 +++++
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
index 03a8438..8be69c6 100644
--- a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
+++ b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
@@ -11,7 +11,7 @@ final class WP_Markdown_Native_Authoritative_Snapshot_Runtime implements WP_Mark
 	private const MAX_BYTES_PER_TABLE = 8388608;
 
 	/** @param array<int,array{table:string,exists:bool,rows?:int,sha256?:string,schema_sha256?:string}> $provenance */
-	public function __construct( private WP_Markdown_Query_Runtime $runtime, private array $provenance, private ?string $database_name = null ) {}
+	public function __construct( private WP_Markdown_Query_Runtime $runtime, private array $provenance, private ?string $database_name = null, private ?array $catalog_observation = null ) {}
 
 	public static function capture( object $database, string $sql, string $prefix ): self {
 		self::trace_runtime_phase( 'capture', $sql );
@@ -28,6 +28,7 @@ public static function capture( object $database, string $sql, string $prefix ):
 
 		$prefixes = self::schema_prefixes( $database, $prefix );
 		$database_name = self::database_name( $connection );
+		$catalog_observation = self::catalog_observation( $connection, $sql );
 		$registry = new WP_Markdown_Native_Table_Registry();
 		$provenance = array();
 		foreach ( $tables as $table ) {
@@ -49,7 +50,11 @@ public static function capture( object $database, string $sql, string $prefix ):
 			$registry->register( $table, $schema, new WP_Markdown_Native_Authoritative_Snapshot_Provider( $rows, $schema ) );
 			$provenance[] = array( 'table' => $table, 'exists' => true, 'rows' => count( $rows ), 'sha256' => hash( 'sha256', self::encode_rows( $rows ) ), 'schema_sha256' => hash( 'sha256', $definition ) );
 		}
-		return new self( new WP_Markdown_Native_Query_Runtime( $registry, database_name: $database_name ), $provenance, $database_name );
+		$catalog_observation = null === $catalog_observation ? null : array(
+			'before' => $catalog_observation,
+			'after'  => self::catalog_observation( $connection, $sql ),
+		);
+		return new self( new WP_Markdown_Native_Query_Runtime( $registry, database_name: $database_name ), $provenance, $database_name, $catalog_observation );
 	}
 
 	private static function trace_runtime_phase( string $phase, ?string $sql = null ): void {
@@ -113,7 +118,24 @@ private function has_explicitly_absent_source( string $sql ): bool {
 
 	/** @return array{read_connection:string,database_sha256:?string,tables:array<int,array{table:string,exists:bool,rows?:int,sha256?:string,schema_sha256?:string}>} */
 	public function provenance(): array {
-		return array( 'read_connection' => 'authoritative_mysql_connection_pre_query', 'database_sha256' => null === $this->database_name ? null : hash( 'sha256', $this->database_name ), 'tables' => $this->provenance );
+		return array_filter(
+			array(
+				'read_connection'     => 'authoritative_mysql_connection_pre_query',
+				'database_sha256'     => null === $this->database_name ? null : hash( 'sha256', $this->database_name ),
+				'tables'              => $this->provenance,
+				'catalog_observation' => $this->catalog_observation,
+			),
+			static fn( mixed $value ): bool => null !== $value
+		);
+	}
+
+	/** @return array{rows:int,sha256:string}|null */
+	private static function catalog_observation( object $connection, string $sql ): ?array {
+		if ( null === WP_Markdown_Native_Schema_Introspection::requested_information_schema_tables( $sql ) ) {
+			return null;
+		}
+		$rows = self::rows( $connection, $sql );
+		return array( 'rows' => count( $rows ), 'sha256' => hash( 'sha256', self::encode_rows( $rows ) ) );
 	}
 
 	/** @return array<int,string> */
diff --git a/tests/smoke-native-shadow-sql-snapshot.php b/tests/smoke-native-shadow-sql-snapshot.php
index a9e79c0..d28296d 100644
--- a/tests/smoke-native-shadow-sql-snapshot.php
+++ b/tests/smoke-native-shadow-sql-snapshot.php
@@ -24,6 +24,7 @@ final class MDI_Snapshot_Connection {
 	public array $global_rows = array( array( 'meta_id' => '1', 'site_id' => '1', 'meta_key' => 'site_name', 'meta_value' => 'Example' ) );
 	/** @var array<int,array<string,mixed>> */
 	public array $plugin_rows = array( array( 'id' => '1', 'name' => 'Agent' ) );
+	public array $catalog_rows = array( array( 'COLUMN_NAME' => 'status', 'DATA_TYPE' => 'varchar', 'CHARACTER_MAXIMUM_LENGTH' => '64', 'IS_NULLABLE' => 'NO' ) );
 	public bool $blog_table_absent = true;
 	public int $errno = 0;
 	/** @var array<int,MDI_Snapshot_Result> */
@@ -66,6 +67,9 @@ public function query( string $sql ): MDI_Snapshot_Result|false {
 		if ( 'SELECT * FROM `wp_2_options` LIMIT 10001' === $sql ) {
 			$result = new MDI_Snapshot_Result( array( array( 'ID' => '1', 'option_value' => 'created' ) ) );
 		}
+		if ( str_starts_with( $sql, 'SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, IS_NULLABLE FROM information_schema.COLUMNS' ) ) {
+			$result = new MDI_Snapshot_Result( $this->catalog_rows );
+		}
 		if ( $result instanceof MDI_Snapshot_Result ) {
 			$this->results[] = $result;
 		}
@@ -300,6 +304,9 @@ public function get_col_info( string $field ): array {
 	'catalog capture snapshots requested physical DDL and independently executes COLUMNS metadata' => array( 'wp_plugin_jobs' ) === array_column( $catalog_columns->provenance()['tables'], 'table' )
 		&& 251 === ( $catalog_result->wpdb_state()['col_info'][1]->type ?? null )
 		&& array( 'status' => '64', 'payload' => '4294967295' ) === array_reduce( $catalog_result->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() ),
+	'catalog capture records stable same-connection source metadata before and after the physical snapshot' => 1 === ( $catalog_columns->provenance()['catalog_observation']['before']['rows'] ?? null )
+		&& ( $catalog_columns->provenance()['catalog_observation']['before'] ?? null ) === ( $catalog_columns->provenance()['catalog_observation']['after'] ?? null )
+		&& 64 === strlen( (string) ( $catalog_columns->provenance()['catalog_observation']['before']['sha256'] ?? '' ) ),
 	'catalog ENGINE remains an explicit unsupported projection after source discovery' => false === $catalog_engine->return_value()
 		&& 'unsupported_column' === ( $catalog_engine->diagnostic()['reason'] ?? null ),
 	'capture results are released after both schema and row reads' => array_reduce( $database->source()->results, static fn( bool $freed, MDI_Snapshot_Result $result ): bool => $freed && $result->freed, true ),

From ea40bc013afc77d25955533f72378938eccb76a8 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 12:35:02 -0400
Subject: [PATCH 22/53] fix(shadow): exclude temporary catalog tables

---
 ...wn-native-authoritative-snapshot-runtime.php | 10 +++++++---
 tests/smoke-native-shadow-sql-snapshot.php      | 17 +++++++++++++++--
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
index 8be69c6..e18078b 100644
--- a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
+++ b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
@@ -10,7 +10,7 @@ final class WP_Markdown_Native_Authoritative_Snapshot_Runtime implements WP_Mark
 	private const MAX_ROWS_PER_TABLE = 10000;
 	private const MAX_BYTES_PER_TABLE = 8388608;
 
-	/** @param array<int,array{table:string,exists:bool,rows?:int,sha256?:string,schema_sha256?:string}> $provenance */
+	/** @param array<int,array{table:string,exists:bool,temporary?:bool,rows?:int,sha256?:string,schema_sha256?:string}> $provenance */
 	public function __construct( private WP_Markdown_Query_Runtime $runtime, private array $provenance, private ?string $database_name = null, private ?array $catalog_observation = null ) {}
 
 	public static function capture( object $database, string $sql, string $prefix ): self {
@@ -47,8 +47,12 @@ public static function capture( object $database, string $sql, string $prefix ):
 				throw new WP_Markdown_Native_Snapshot_Input_Exception( 'markdown_db_native_snapshot_input_unavailable', 'source_schema_unavailable' );
 			}
 			$rows = self::rows( $connection, 'SELECT * FROM ' . $quoted . ' LIMIT ' . ( self::MAX_ROWS_PER_TABLE + 1 ) );
-			$registry->register( $table, $schema, new WP_Markdown_Native_Authoritative_Snapshot_Provider( $rows, $schema ) );
-			$provenance[] = array( 'table' => $table, 'exists' => true, 'rows' => count( $rows ), 'sha256' => hash( 'sha256', self::encode_rows( $rows ) ), 'schema_sha256' => hash( 'sha256', $definition ) );
+			$temporary = 1 === preg_match( '/^CREATE\s+TEMPORARY\s+TABLE\b/i', $definition );
+			// MySQL omits temporary tables from information_schema, despite SHOW CREATE exposing them.
+			if ( ! $temporary || null === $catalog_observation ) {
+				$registry->register( $table, $schema, new WP_Markdown_Native_Authoritative_Snapshot_Provider( $rows, $schema ) );
+			}
+			$provenance[] = array( 'table' => $table, 'exists' => true, 'temporary' => $temporary, 'rows' => count( $rows ), 'sha256' => hash( 'sha256', self::encode_rows( $rows ) ), 'schema_sha256' => hash( 'sha256', $definition ) );
 		}
 		$catalog_observation = null === $catalog_observation ? null : array(
 			'before' => $catalog_observation,
diff --git a/tests/smoke-native-shadow-sql-snapshot.php b/tests/smoke-native-shadow-sql-snapshot.php
index d28296d..6c79749 100644
--- a/tests/smoke-native-shadow-sql-snapshot.php
+++ b/tests/smoke-native-shadow-sql-snapshot.php
@@ -41,6 +41,8 @@ public function query( string $sql ): MDI_Snapshot_Result|false {
 			$result = new MDI_Snapshot_Result( array( array( 'Table' => 'agents', 'Create Table' => 'CREATE TABLE `agents` (`id` bigint(20) unsigned NOT NULL, `name` varchar(255) NOT NULL, PRIMARY KEY (`id`))' ) ) );
 		} elseif ( 'SHOW CREATE TABLE `wp_plugin_jobs`' === $sql ) {
 			$result = new MDI_Snapshot_Result( array( array( 'Table' => 'wp_plugin_jobs', 'Create Table' => 'CREATE TABLE `wp_plugin_jobs` (`id` bigint(20) unsigned NOT NULL, `status` varchar(64) NOT NULL, `payload` longtext NOT NULL, PRIMARY KEY (`id`))' ) ) );
+		} elseif ( 'SHOW CREATE TABLE `wp_temporary_jobs`' === $sql ) {
+			$result = new MDI_Snapshot_Result( array( array( 'Table' => 'wp_temporary_jobs', 'Create Table' => 'CREATE TEMPORARY TABLE `wp_temporary_jobs` (`id` bigint(20) unsigned NOT NULL, `status` varchar(64) NOT NULL, PRIMARY KEY (`id`))' ) ) );
 		} elseif ( 'SHOW CREATE TABLE `wp_2_options`' === $sql && $this->blog_table_absent ) {
 			$this->errno = 1146;
 			return false;
@@ -64,11 +66,14 @@ public function query( string $sql ): MDI_Snapshot_Result|false {
 		if ( 'SELECT * FROM `wp_plugin_jobs` LIMIT 10001' === $sql ) {
 			$result = new MDI_Snapshot_Result( array() );
 		}
+		if ( 'SELECT * FROM `wp_temporary_jobs` LIMIT 10001' === $sql ) {
+			$result = new MDI_Snapshot_Result( array() );
+		}
 		if ( 'SELECT * FROM `wp_2_options` LIMIT 10001' === $sql ) {
 			$result = new MDI_Snapshot_Result( array( array( 'ID' => '1', 'option_value' => 'created' ) ) );
 		}
-		if ( str_starts_with( $sql, 'SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, IS_NULLABLE FROM information_schema.COLUMNS' ) ) {
-			$result = new MDI_Snapshot_Result( $this->catalog_rows );
+		if ( str_starts_with( $sql, 'SELECT COLUMN_NAME' ) && str_contains( $sql, 'FROM information_schema.COLUMNS' ) ) {
+			$result = new MDI_Snapshot_Result( str_contains( $sql, "'wp_temporary_jobs'" ) ? array() : $this->catalog_rows );
 		}
 		if ( $result instanceof MDI_Snapshot_Result ) {
 			$this->results[] = $result;
@@ -259,6 +264,12 @@ public function get_col_info( string $field ): array {
 );
 $catalog_result = $catalog_columns->execute( new WP_Markdown_Query_Request( "SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, IS_NULLABLE FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_plugin_jobs' AND COLUMN_NAME IN ('status', 'payload')", 'wp_' ) );
 $catalog_engine = $catalog_columns->execute( new WP_Markdown_Query_Request( "SELECT ENGINE FROM information_schema.TABLES WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_plugin_jobs'", 'wp_' ) );
+$temporary_catalog = WP_Markdown_Native_Authoritative_Snapshot_Runtime::capture(
+	$database,
+	"SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_temporary_jobs'",
+	'wp_'
+);
+$temporary_catalog_result = $temporary_catalog->execute( new WP_Markdown_Query_Request( "SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_temporary_jobs'", 'wp_' ) );
 $capture_count_at_bound = count( $database->source()->results );
 $bounded->capture_input( 'SELECT ID, post_title FROM wp_posts', $database );
 $bounded->observe( 'SELECT ID, post_title FROM wp_posts', 1, $database );
@@ -307,6 +318,8 @@ public function get_col_info( string $field ): array {
 	'catalog capture records stable same-connection source metadata before and after the physical snapshot' => 1 === ( $catalog_columns->provenance()['catalog_observation']['before']['rows'] ?? null )
 		&& ( $catalog_columns->provenance()['catalog_observation']['before'] ?? null ) === ( $catalog_columns->provenance()['catalog_observation']['after'] ?? null )
 		&& 64 === strlen( (string) ( $catalog_columns->provenance()['catalog_observation']['before']['sha256'] ?? '' ) ),
+	'temporary source tables remain absent from information_schema catalog snapshots' => true === ( $temporary_catalog->provenance()['tables'][0]['temporary'] ?? null )
+		&& array() === $temporary_catalog_result->wpdb_state()['last_result'],
 	'catalog ENGINE remains an explicit unsupported projection after source discovery' => false === $catalog_engine->return_value()
 		&& 'unsupported_column' === ( $catalog_engine->diagnostic()['reason'] ?? null ),
 	'capture results are released after both schema and row reads' => array_reduce( $database->source()->results, static fn( bool $freed, MDI_Snapshot_Result $result ): bool => $freed && $result->freed, true ),

From 0d663610eaf442562639f43e1e89026d799a37fe Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 12:45:03 -0400
Subject: [PATCH 23/53] fix(shadow): capture permanent catalog schemas

---
 ...-native-authoritative-snapshot-runtime.php | 76 ++++++++++++++-----
 ...lass-wp-markdown-native-query-executor.php | 12 ++-
 .../class-wp-markdown-native-query-parser.php | 12 ++-
 tests/smoke-native-shadow-sql-snapshot.php    | 31 +++++---
 4 files changed, 95 insertions(+), 36 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
index e18078b..53e1159 100644
--- a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
+++ b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
@@ -11,7 +11,7 @@ final class WP_Markdown_Native_Authoritative_Snapshot_Runtime implements WP_Mark
 	private const MAX_BYTES_PER_TABLE = 8388608;
 
 	/** @param array<int,array{table:string,exists:bool,temporary?:bool,rows?:int,sha256?:string,schema_sha256?:string}> $provenance */
-	public function __construct( private WP_Markdown_Query_Runtime $runtime, private array $provenance, private ?string $database_name = null, private ?array $catalog_observation = null ) {}
+	public function __construct( private WP_Markdown_Query_Runtime $runtime, private array $provenance, private ?string $database_name = null ) {}
 
 	public static function capture( object $database, string $sql, string $prefix ): self {
 		self::trace_runtime_phase( 'capture', $sql );
@@ -28,7 +28,7 @@ public static function capture( object $database, string $sql, string $prefix ):
 
 		$prefixes = self::schema_prefixes( $database, $prefix );
 		$database_name = self::database_name( $connection );
-		$catalog_observation = self::catalog_observation( $connection, $sql );
+		$catalog_tables = WP_Markdown_Native_Schema_Introspection::requested_information_schema_tables( $sql );
 		$registry = new WP_Markdown_Native_Table_Registry();
 		$provenance = array();
 		foreach ( $tables as $table ) {
@@ -46,19 +46,25 @@ public static function capture( object $database, string $sql, string $prefix ):
 			if ( ! $schema instanceof WP_Markdown_Native_Table_Schema ) {
 				throw new WP_Markdown_Native_Snapshot_Input_Exception( 'markdown_db_native_snapshot_input_unavailable', 'source_schema_unavailable' );
 			}
-			$rows = self::rows( $connection, 'SELECT * FROM ' . $quoted . ' LIMIT ' . ( self::MAX_ROWS_PER_TABLE + 1 ) );
 			$temporary = 1 === preg_match( '/^CREATE\s+TEMPORARY\s+TABLE\b/i', $definition );
-			// MySQL omits temporary tables from information_schema, despite SHOW CREATE exposing them.
-			if ( ! $temporary || null === $catalog_observation ) {
-				$registry->register( $table, $schema, new WP_Markdown_Native_Authoritative_Snapshot_Provider( $rows, $schema ) );
+			if ( $temporary && is_array( $catalog_tables ) && in_array( $table, $catalog_tables, true ) ) {
+				// SHOW CREATE resolves the session temporary table; metadata must come from the permanent catalog.
+				$definition = self::permanent_catalog_definition( $connection, $table );
+				$compiled = '' === $definition ? array() : WP_Markdown_Native_Schema_Catalog::compile( $definition, $prefixes, array( $table ) );
+				$schema_definition = 1 === count( $compiled ) ? reset( $compiled ) : null;
+				$schema = is_array( $schema_definition ) ? WP_Markdown_Native_Schema_Catalog::indexed_snapshot_schema( $schema_definition ) : null;
+				if ( ! $schema instanceof WP_Markdown_Native_Table_Schema ) {
+					throw new WP_Markdown_Native_Snapshot_Input_Exception( 'markdown_db_native_snapshot_input_unavailable', 'permanent_catalog_schema_unavailable' );
+				}
+				$registry->register( $table, $schema, new WP_Markdown_Native_Authoritative_Snapshot_Provider( array(), $schema ) );
+				$provenance[] = array( 'table' => $table, 'exists' => true, 'temporary' => true, 'schema_sha256' => hash( 'sha256', $definition ) );
+				continue;
 			}
+			$rows = self::rows( $connection, 'SELECT * FROM ' . $quoted . ' LIMIT ' . ( self::MAX_ROWS_PER_TABLE + 1 ) );
+			$registry->register( $table, $schema, new WP_Markdown_Native_Authoritative_Snapshot_Provider( $rows, $schema ) );
 			$provenance[] = array( 'table' => $table, 'exists' => true, 'temporary' => $temporary, 'rows' => count( $rows ), 'sha256' => hash( 'sha256', self::encode_rows( $rows ) ), 'schema_sha256' => hash( 'sha256', $definition ) );
 		}
-		$catalog_observation = null === $catalog_observation ? null : array(
-			'before' => $catalog_observation,
-			'after'  => self::catalog_observation( $connection, $sql ),
-		);
-		return new self( new WP_Markdown_Native_Query_Runtime( $registry, database_name: $database_name ), $provenance, $database_name, $catalog_observation );
+		return new self( new WP_Markdown_Native_Query_Runtime( $registry, database_name: $database_name ), $provenance, $database_name );
 	}
 
 	private static function trace_runtime_phase( string $phase, ?string $sql = null ): void {
@@ -66,17 +72,23 @@ private static function trace_runtime_phase( string $phase, ?string $sql = null
 		if ( ! is_string( $path ) || '' === $path ) {
 			return;
 		}
+		if ( ( is_file( $path ) ? (int) filesize( $path ) : 0 ) >= 65536 ) {
+			return;
+		}
 		$event = array( 'phase' => $phase, 'file_sha256' => hash_file( 'sha256', __FILE__ ) );
-		if ( null !== $sql ) {
+		if ( null !== $sql && strlen( $sql ) <= 65536 ) {
 			try {
 				$event['sql_sha256'] = hash( 'sha256', $sql );
-				$event['token_types'] = array_map( static fn( WP_Markdown_Native_SQL_Token $token ): string => $token->type(), ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( $sql ) );
+				$event['token_types'] = array_slice( array_map( static fn( WP_Markdown_Native_SQL_Token $token ): string => $token->type(), ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( $sql ) ), 0, 128 );
 				$event['table_count'] = count( self::tables_in( $sql ) );
 			} catch ( WP_Markdown_Native_Snapshot_Input_Exception|WP_Markdown_Native_SQL_Parse_Error ) {
 				$event['token_types'] = array( 'parse_error' );
 			}
 		}
-		file_put_contents( $path, json_encode( $event, JSON_UNESCAPED_SLASHES ) . "\n", FILE_APPEND | LOCK_EX );
+		$encoded = json_encode( $event, JSON_UNESCAPED_SLASHES ) . "\n";
+		if ( strlen( $encoded ) <= 4096 && ( is_file( $path ) ? (int) filesize( $path ) : 0 ) + strlen( $encoded ) <= 65536 ) {
+			file_put_contents( $path, $encoded, FILE_APPEND | LOCK_EX );
+		}
 	}
 
 	/** @return array<int,string> */
@@ -127,19 +139,41 @@ public function provenance(): array {
 				'read_connection'     => 'authoritative_mysql_connection_pre_query',
 				'database_sha256'     => null === $this->database_name ? null : hash( 'sha256', $this->database_name ),
 				'tables'              => $this->provenance,
-				'catalog_observation' => $this->catalog_observation,
 			),
 			static fn( mixed $value ): bool => null !== $value
 		);
 	}
 
-	/** @return array{rows:int,sha256:string}|null */
-	private static function catalog_observation( object $connection, string $sql ): ?array {
-		if ( null === WP_Markdown_Native_Schema_Introspection::requested_information_schema_tables( $sql ) ) {
-			return null;
+	private static function permanent_catalog_definition( object $connection, string $table ): string {
+		$escaped = str_replace( "'", "''", $table );
+		$rows = self::rows( $connection, "SELECT COLUMN_NAME, COLUMN_TYPE, IS_NULLABLE, COLUMN_KEY, EXTRA, COLUMN_DEFAULT FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = '{$escaped}' ORDER BY ORDINAL_POSITION" );
+		if ( array() === $rows ) {
+			return '';
+		}
+		$columns = array();
+		$primary = array();
+		foreach ( $rows as $row ) {
+			$name = (string) ( $row['COLUMN_NAME'] ?? '' );
+			$type = (string) ( $row['COLUMN_TYPE'] ?? '' );
+			if ( 1 !== preg_match( '/^[A-Za-z0-9_]+$/', $name ) || 1 !== preg_match( '/^[A-Za-z]+(?:\([0-9,]+\))?(?:\s+unsigned)?$/i', $type ) ) {
+				return '';
+			}
+			$line = '`' . $name . '` ' . $type . ( 'NO' === ( $row['IS_NULLABLE'] ?? null ) ? ' NOT NULL' : '' );
+			if ( null !== ( $row['COLUMN_DEFAULT'] ?? null ) ) {
+				$line .= " DEFAULT '" . str_replace( "'", "''", (string) $row['COLUMN_DEFAULT'] ) . "'";
+			}
+			if ( str_contains( strtolower( (string) ( $row['EXTRA'] ?? '' ) ), 'auto_increment' ) ) {
+				$line .= ' AUTO_INCREMENT';
+			}
+			$columns[] = $line;
+			if ( 'PRI' === ( $row['COLUMN_KEY'] ?? null ) ) {
+				$primary[] = '`' . $name . '`';
+			}
+		}
+		if ( array() !== $primary ) {
+			$columns[] = 'PRIMARY KEY (' . implode( ',', $primary ) . ')';
 		}
-		$rows = self::rows( $connection, $sql );
-		return array( 'rows' => count( $rows ), 'sha256' => hash( 'sha256', self::encode_rows( $rows ) ) );
+		return 'CREATE TABLE `' . $table . '` (' . implode( ',', $columns ) . ')';
 	}
 
 	/** @return array<int,string> */
diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 94e6936..f89d955 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -146,16 +146,22 @@ private static function trace_runtime_phase( string $phase, ?string $sql = null
 		if ( ! is_string( $path ) || '' === $path ) {
 			return;
 		}
+		if ( ( is_file( $path ) ? (int) filesize( $path ) : 0 ) >= 65536 ) {
+			return;
+		}
 		$event = array( 'phase' => $phase, 'file_sha256' => hash_file( 'sha256', __FILE__ ) );
-		if ( null !== $sql ) {
+		if ( null !== $sql && strlen( $sql ) <= 65536 ) {
 			try {
 				$event['sql_sha256'] = hash( 'sha256', $sql );
-				$event['token_types'] = array_map( static fn( WP_Markdown_Native_SQL_Token $token ): string => $token->type(), ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( $sql ) );
+				$event['token_types'] = array_slice( array_map( static fn( WP_Markdown_Native_SQL_Token $token ): string => $token->type(), ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( $sql ) ), 0, 128 );
 			} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
 				$event['token_types'] = array( 'parse_error' );
 			}
 		}
-		file_put_contents( $path, json_encode( $event, JSON_UNESCAPED_SLASHES ) . "\n", FILE_APPEND | LOCK_EX );
+		$encoded = json_encode( $event, JSON_UNESCAPED_SLASHES ) . "\n";
+		if ( strlen( $encoded ) <= 4096 && ( is_file( $path ) ? (int) filesize( $path ) : 0 ) + strlen( $encoded ) <= 65536 ) {
+			file_put_contents( $path, $encoded, FILE_APPEND | LOCK_EX );
+		}
 	}
 
 	/** Execute source-free typed scalar expressions as the one-row SQL result. */
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index c9b8223..583f00f 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -28,16 +28,22 @@ private static function trace_runtime_phase( string $phase, ?string $sql = null
 		if ( ! is_string( $path ) || '' === $path ) {
 			return;
 		}
+		if ( ( is_file( $path ) ? (int) filesize( $path ) : 0 ) >= 65536 ) {
+			return;
+		}
 		$event = array( 'phase' => $phase, 'file_sha256' => hash_file( 'sha256', __FILE__ ) );
-		if ( null !== $sql ) {
+		if ( null !== $sql && strlen( $sql ) <= 65536 ) {
 			try {
 				$event['sql_sha256'] = hash( 'sha256', $sql );
-				$event['token_types'] = array_map( static fn( WP_Markdown_Native_SQL_Token $token ): string => $token->type(), ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( $sql ) );
+				$event['token_types'] = array_slice( array_map( static fn( WP_Markdown_Native_SQL_Token $token ): string => $token->type(), ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( $sql ) ), 0, 128 );
 			} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
 				$event['token_types'] = array( 'parse_error' );
 			}
 		}
-		file_put_contents( $path, json_encode( $event, JSON_UNESCAPED_SLASHES ) . "\n", FILE_APPEND | LOCK_EX );
+		$encoded = json_encode( $event, JSON_UNESCAPED_SLASHES ) . "\n";
+		if ( strlen( $encoded ) <= 4096 && ( is_file( $path ) ? (int) filesize( $path ) : 0 ) + strlen( $encoded ) <= 65536 ) {
+			file_put_contents( $path, $encoded, FILE_APPEND | LOCK_EX );
+		}
 	}
 
 	/**
diff --git a/tests/smoke-native-shadow-sql-snapshot.php b/tests/smoke-native-shadow-sql-snapshot.php
index 6c79749..e714bf7 100644
--- a/tests/smoke-native-shadow-sql-snapshot.php
+++ b/tests/smoke-native-shadow-sql-snapshot.php
@@ -25,6 +25,7 @@ final class MDI_Snapshot_Connection {
 	/** @var array<int,array<string,mixed>> */
 	public array $plugin_rows = array( array( 'id' => '1', 'name' => 'Agent' ) );
 	public array $catalog_rows = array( array( 'COLUMN_NAME' => 'status', 'DATA_TYPE' => 'varchar', 'CHARACTER_MAXIMUM_LENGTH' => '64', 'IS_NULLABLE' => 'NO' ) );
+	public bool $temporary_permanent_schema_exists = false;
 	public bool $blog_table_absent = true;
 	public int $errno = 0;
 	/** @var array<int,MDI_Snapshot_Result> */
@@ -73,7 +74,11 @@ public function query( string $sql ): MDI_Snapshot_Result|false {
 			$result = new MDI_Snapshot_Result( array( array( 'ID' => '1', 'option_value' => 'created' ) ) );
 		}
 		if ( str_starts_with( $sql, 'SELECT COLUMN_NAME' ) && str_contains( $sql, 'FROM information_schema.COLUMNS' ) ) {
-			$result = new MDI_Snapshot_Result( str_contains( $sql, "'wp_temporary_jobs'" ) ? array() : $this->catalog_rows );
+			if ( str_contains( $sql, "TABLE_NAME = 'wp_temporary_jobs'" ) && str_contains( $sql, 'COLUMN_TYPE' ) ) {
+				$result = new MDI_Snapshot_Result( $this->temporary_permanent_schema_exists ? array( array( 'COLUMN_NAME' => 'permanent_id', 'COLUMN_TYPE' => 'bigint(20) unsigned', 'IS_NULLABLE' => 'NO', 'COLUMN_KEY' => 'PRI', 'EXTRA' => '', 'COLUMN_DEFAULT' => null ) ) : array() );
+			} else {
+				$result = new MDI_Snapshot_Result( str_contains( $sql, "'wp_temporary_jobs'" ) ? array() : $this->catalog_rows );
+			}
 		}
 		if ( $result instanceof MDI_Snapshot_Result ) {
 			$this->results[] = $result;
@@ -264,12 +269,22 @@ public function get_col_info( string $field ): array {
 );
 $catalog_result = $catalog_columns->execute( new WP_Markdown_Query_Request( "SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, IS_NULLABLE FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_plugin_jobs' AND COLUMN_NAME IN ('status', 'payload')", 'wp_' ) );
 $catalog_engine = $catalog_columns->execute( new WP_Markdown_Query_Request( "SELECT ENGINE FROM information_schema.TABLES WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_plugin_jobs'", 'wp_' ) );
-$temporary_catalog = WP_Markdown_Native_Authoritative_Snapshot_Runtime::capture(
+$temporary_catalog_reason = null;
+try {
+	WP_Markdown_Native_Authoritative_Snapshot_Runtime::capture(
+		$database,
+		"SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_temporary_jobs'",
+		'wp_'
+	);
+} catch ( WP_Markdown_Native_Snapshot_Input_Exception $error ) {
+	$temporary_catalog_reason = $error->diagnostic()['reason'];
+}
+$database->source()->temporary_permanent_schema_exists = true;
+$temporary_shadow_catalog = WP_Markdown_Native_Authoritative_Snapshot_Runtime::capture(
 	$database,
 	"SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_temporary_jobs'",
 	'wp_'
-);
-$temporary_catalog_result = $temporary_catalog->execute( new WP_Markdown_Query_Request( "SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_temporary_jobs'", 'wp_' ) );
+)->execute( new WP_Markdown_Query_Request( "SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '' AND TABLE_NAME = 'wp_temporary_jobs'", 'wp_' ) );
 $capture_count_at_bound = count( $database->source()->results );
 $bounded->capture_input( 'SELECT ID, post_title FROM wp_posts', $database );
 $bounded->observe( 'SELECT ID, post_title FROM wp_posts', 1, $database );
@@ -315,11 +330,9 @@ public function get_col_info( string $field ): array {
 	'catalog capture snapshots requested physical DDL and independently executes COLUMNS metadata' => array( 'wp_plugin_jobs' ) === array_column( $catalog_columns->provenance()['tables'], 'table' )
 		&& 251 === ( $catalog_result->wpdb_state()['col_info'][1]->type ?? null )
 		&& array( 'status' => '64', 'payload' => '4294967295' ) === array_reduce( $catalog_result->wpdb_state()['last_result'], static function ( array $values, object $row ): array { $values[ $row->COLUMN_NAME ] = $row->CHARACTER_MAXIMUM_LENGTH; return $values; }, array() ),
-	'catalog capture records stable same-connection source metadata before and after the physical snapshot' => 1 === ( $catalog_columns->provenance()['catalog_observation']['before']['rows'] ?? null )
-		&& ( $catalog_columns->provenance()['catalog_observation']['before'] ?? null ) === ( $catalog_columns->provenance()['catalog_observation']['after'] ?? null )
-		&& 64 === strlen( (string) ( $catalog_columns->provenance()['catalog_observation']['before']['sha256'] ?? '' ) ),
-	'temporary source tables remain absent from information_schema catalog snapshots' => true === ( $temporary_catalog->provenance()['tables'][0]['temporary'] ?? null )
-		&& array() === $temporary_catalog_result->wpdb_state()['last_result'],
+	'catalog capture does not replay the observed metadata SQL for diagnostic receipts' => ! isset( $catalog_columns->provenance()['catalog_observation'] ),
+	'temporary catalog capture is explicitly unavailable when no permanent schema exists' => 'permanent_catalog_schema_unavailable' === $temporary_catalog_reason,
+	'temporary tables use independently captured permanent catalog metadata when names shadow' => array( 'permanent_id' ) === array_map( static fn( object $row ): string => $row->COLUMN_NAME, $temporary_shadow_catalog->wpdb_state()['last_result'] ),
 	'catalog ENGINE remains an explicit unsupported projection after source discovery' => false === $catalog_engine->return_value()
 		&& 'unsupported_column' === ( $catalog_engine->diagnostic()['reason'] ?? null ),
 	'capture results are released after both schema and row reads' => array_reduce( $database->source()->results, static fn( bool $freed, MDI_Snapshot_Result $result ): bool => $freed && $result->freed, true ),

From c181939eddec0245b07caf6efba7efd27dd0c67d Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 12:48:53 -0400
Subject: [PATCH 24/53] fix(shadow): atomically bound trace output

---
 ...down-native-authoritative-snapshot-runtime.php | 15 +++++++++++++--
 .../class-wp-markdown-native-query-executor.php   | 15 +++++++++++++--
 .../class-wp-markdown-native-query-parser.php     | 15 +++++++++++++--
 3 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
index 53e1159..0c9eb04 100644
--- a/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
+++ b/inc/native/class-wp-markdown-native-authoritative-snapshot-runtime.php
@@ -86,8 +86,19 @@ private static function trace_runtime_phase( string $phase, ?string $sql = null
 			}
 		}
 		$encoded = json_encode( $event, JSON_UNESCAPED_SLASHES ) . "\n";
-		if ( strlen( $encoded ) <= 4096 && ( is_file( $path ) ? (int) filesize( $path ) : 0 ) + strlen( $encoded ) <= 65536 ) {
-			file_put_contents( $path, $encoded, FILE_APPEND | LOCK_EX );
+		if ( strlen( $encoded ) <= 4096 && false !== ( $trace = @fopen( $path, 'c' ) ) ) {
+			try {
+				if ( flock( $trace, LOCK_EX ) ) {
+					$size = fstat( $trace )['size'] ?? 0;
+					if ( $size + strlen( $encoded ) <= 65536 ) {
+						fseek( $trace, 0, SEEK_END );
+						fwrite( $trace, $encoded );
+					}
+					flock( $trace, LOCK_UN );
+				}
+			} finally {
+				fclose( $trace );
+			}
 		}
 	}
 
diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index f89d955..9259075 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -159,8 +159,19 @@ private static function trace_runtime_phase( string $phase, ?string $sql = null
 			}
 		}
 		$encoded = json_encode( $event, JSON_UNESCAPED_SLASHES ) . "\n";
-		if ( strlen( $encoded ) <= 4096 && ( is_file( $path ) ? (int) filesize( $path ) : 0 ) + strlen( $encoded ) <= 65536 ) {
-			file_put_contents( $path, $encoded, FILE_APPEND | LOCK_EX );
+		if ( strlen( $encoded ) <= 4096 && false !== ( $trace = @fopen( $path, 'c' ) ) ) {
+			try {
+				if ( flock( $trace, LOCK_EX ) ) {
+					$size = fstat( $trace )['size'] ?? 0;
+					if ( $size + strlen( $encoded ) <= 65536 ) {
+						fseek( $trace, 0, SEEK_END );
+						fwrite( $trace, $encoded );
+					}
+					flock( $trace, LOCK_UN );
+				}
+			} finally {
+				fclose( $trace );
+			}
 		}
 	}
 
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index 583f00f..e5eb335 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -41,8 +41,19 @@ private static function trace_runtime_phase( string $phase, ?string $sql = null
 			}
 		}
 		$encoded = json_encode( $event, JSON_UNESCAPED_SLASHES ) . "\n";
-		if ( strlen( $encoded ) <= 4096 && ( is_file( $path ) ? (int) filesize( $path ) : 0 ) + strlen( $encoded ) <= 65536 ) {
-			file_put_contents( $path, $encoded, FILE_APPEND | LOCK_EX );
+		if ( strlen( $encoded ) <= 4096 && false !== ( $trace = @fopen( $path, 'c' ) ) ) {
+			try {
+				if ( flock( $trace, LOCK_EX ) ) {
+					$size = fstat( $trace )['size'] ?? 0;
+					if ( $size + strlen( $encoded ) <= 65536 ) {
+						fseek( $trace, 0, SEEK_END );
+						fwrite( $trace, $encoded );
+					}
+					flock( $trace, LOCK_UN );
+				}
+			} finally {
+				fclose( $trace );
+			}
 		}
 	}
 

From 9d87378727de996dbb74e973a6b333ab463636c3 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 14:13:25 -0400
Subject: [PATCH 25/53] fix(native): bound post title lookups

---
 REMAINING_102_GAPS.md                           | 17 +++++++++++++++++
 .../class-wp-markdown-native-query-runtime.php  |  8 ++++++++
 tests/smoke-native-like-query.php               |  7 +++++++
 3 files changed, 32 insertions(+)
 create mode 100644 REMAINING_102_GAPS.md

diff --git a/REMAINING_102_GAPS.md b/REMAINING_102_GAPS.md
new file mode 100644
index 0000000..83cd6e4
--- /dev/null
+++ b/REMAINING_102_GAPS.md
@@ -0,0 +1,17 @@
+# Remaining Native Consumer Gaps
+
+The exact full DME1053 pair at candidate `99e032be6c5cf65b85a64ce863eb0e0065084682` recorded native 942 passed, 70 failures, 32 errors, and 9 skipped. The MySQL control recorded 1,022 passed, 24 errors, and 7 skipped.
+
+## Raw-Diagnostic Classification
+
+- The MySQL control errors are WP_CLI bootstrap failures and must remain separate from native engine parity.
+- Native errors include the same missing WP_CLI class plus three physical `mysqli` root-access failures in `VenueProfileMutationsTest`; neither proves a native SQL mismatch.
+- Native assertion failures include harness/application state differences such as user initialization and the physical-`mysqli` expectation in `WordPressLifecycleTest`.
+- A repeated native query symptom is empty event candidate sets in `EventDateQueryAbilitiesTest` and duplicate/upsert paths. The posts schema did not classify exact `post_title` predicates as bounded lookups. This branch adds ASCII case-insensitive `=` and `IN` support, with non-ASCII values failing closed.
+
+## Still Unresolved
+
+- Full Unicode MySQL collation semantics for title lookups remain unsupported.
+- Physical `mysqli` and WP_CLI-dependent tests require separate Codebox/bootstrap ownership.
+- Transaction semantics require a dedicated end-to-end framework repair; reporting an InnoDB engine string alone would not supply them.
+- The remaining native assertions need paired, per-test diagnosis after this focused repair; aggregate full-suite counts are not parity evidence.
diff --git a/inc/native/class-wp-markdown-native-query-runtime.php b/inc/native/class-wp-markdown-native-query-runtime.php
index fc24c41..409d81e 100644
--- a/inc/native/class-wp-markdown-native-query-runtime.php
+++ b/inc/native/class-wp-markdown-native-query-runtime.php
@@ -106,6 +106,14 @@ public static function posts_schema(): WP_Markdown_Native_Table_Schema {
 					'post_author' => array( 'lookup_operators' => array( '=', 'IN' ) ),
 					'post_parent' => array( 'lookup_operators' => array( '=', 'IN' ) ),
 					'post_type' => array( 'lookup_operators' => array( '=', 'IN' ) ),
+					// Duplicate-event discovery uses a title equality candidate set.
+					// Keep its file-backed scan bounded to ASCII comparisons instead
+					// of assuming MySQL's full Unicode collation.
+					'post_title' => array(
+						'normalizer'       => array( self::class, 'normalize_ascii_ci' ),
+						'lookup_operators' => array( '=', 'IN' ),
+						'lookup_validator' => static fn( array $values ): bool => self::all_ascii_strings( $values ),
+					),
 					// WordPress resolves a permalink by slug, so post_name is the
 					// lookup every front-end request depends on. Slugs are
 					// sanitized to ASCII, and a non-ASCII slug fails closed
diff --git a/tests/smoke-native-like-query.php b/tests/smoke-native-like-query.php
index 0f202dc..a3e9337 100644
--- a/tests/smoke-native-like-query.php
+++ b/tests/smoke-native-like-query.php
@@ -28,6 +28,9 @@
 $contains = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title LIKE '%Hello%'", 'wp_' ) );
 $prefix = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title LIKE 'Good%'", 'wp_' ) );
 $ci = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title LIKE '%hello%'", 'wp_' ) );
+$exact = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title = 'hello world'", 'wp_' ) );
+$candidates = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title IN ('goodbye moon', 'unrelated') ORDER BY ID", 'wp_' ) );
+$exact_unicode = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title = 'Café'", 'wp_' ) );
 $content_like = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_content LIKE '%hello%'", 'wp_' ) );
 $unicode = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title LIKE '%Café%'", 'wp_' ) );
 $integer = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE ID LIKE '1%'", 'wp_' ) );
@@ -42,6 +45,10 @@
 	'a contains-pattern matches ASCII titles' => array( '11' ) === $ids( $contains ),
 	'a prefix-pattern matches ASCII titles' => array( '12' ) === $ids( $prefix ),
 	'LIKE matching is ASCII case-insensitive' => array( '11' ) === $ids( $ci ),
+	'an exact title lookup is ASCII case-insensitive' => array( '11' ) === $ids( $exact ),
+	'a bounded title candidate set is indexable' => array( '12', '13' ) === $ids( $candidates ),
+	'a non-ASCII exact title lookup fails closed' => false === $exact_unicode->return_value()
+		&& 'unsupported_lookup' === ( $exact_unicode->diagnostic()['reason'] ?? null ),
 	'LIKE can scan post_content' => array( '12' ) === $ids( $content_like ),
 	'a non-ASCII LIKE pattern fails closed' => false === $unicode->return_value()
 		&& 'unsupported_lookup' === ( $unicode->diagnostic()['reason'] ?? null ),

From b85dfe1ada169bf9b67e66f2633b2c38691d1ceb Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 14:26:21 -0400
Subject: [PATCH 26/53] fix(native): cap title lookup source work

---
 REMAINING_102_GAPS.md                         |  3 +-
 ...class-wp-markdown-native-query-runtime.php |  3 +-
 ...ass-wp-markdown-native-table-providers.php | 25 +++++++++++++
 tests/smoke-native-like-query.php             |  4 ++
 .../smoke-native-post-title-lookup-budget.php | 37 +++++++++++++++++++
 5 files changed, 70 insertions(+), 2 deletions(-)
 create mode 100644 tests/smoke-native-post-title-lookup-budget.php

diff --git a/REMAINING_102_GAPS.md b/REMAINING_102_GAPS.md
index 83cd6e4..bc76e0f 100644
--- a/REMAINING_102_GAPS.md
+++ b/REMAINING_102_GAPS.md
@@ -7,11 +7,12 @@ The exact full DME1053 pair at candidate `99e032be6c5cf65b85a64ce863eb0e00650846
 - The MySQL control errors are WP_CLI bootstrap failures and must remain separate from native engine parity.
 - Native errors include the same missing WP_CLI class plus three physical `mysqli` root-access failures in `VenueProfileMutationsTest`; neither proves a native SQL mismatch.
 - Native assertion failures include harness/application state differences such as user initialization and the physical-`mysqli` expectation in `WordPressLifecycleTest`.
-- A repeated native query symptom is empty event candidate sets in `EventDateQueryAbilitiesTest` and duplicate/upsert paths. The posts schema did not classify exact `post_title` predicates as bounded lookups. This branch adds ASCII case-insensitive `=` and `IN` support, with non-ASCII values failing closed.
+- A repeated native query symptom is empty event candidate sets in `EventDateQueryAbilitiesTest` and duplicate/upsert paths. The posts schema did not classify exact `post_title` predicates as lookups. This branch supports ASCII case-insensitive, trailing-space-padded `=` and `IN` comparisons, with non-ASCII values failing closed. A title lookup without a reusable scoped snapshot explicitly fails after 1,024 canonical source files; ASCII validation is a collation constraint, not a scan-cost bound.
 
 ## Still Unresolved
 
 - Full Unicode MySQL collation semantics for title lookups remain unsupported.
+- Title lookups over larger uncached canonical corpora require a reusable source index before they can execute without the explicit 1,024-file work limit.
 - Physical `mysqli` and WP_CLI-dependent tests require separate Codebox/bootstrap ownership.
 - Transaction semantics require a dedicated end-to-end framework repair; reporting an InnoDB engine string alone would not supply them.
 - The remaining native assertions need paired, per-test diagnosis after this focused repair; aggregate full-suite counts are not parity evidence.
diff --git a/inc/native/class-wp-markdown-native-query-runtime.php b/inc/native/class-wp-markdown-native-query-runtime.php
index 409d81e..baabb26 100644
--- a/inc/native/class-wp-markdown-native-query-runtime.php
+++ b/inc/native/class-wp-markdown-native-query-runtime.php
@@ -107,10 +107,11 @@ public static function posts_schema(): WP_Markdown_Native_Table_Schema {
 					'post_parent' => array( 'lookup_operators' => array( '=', 'IN' ) ),
 					'post_type' => array( 'lookup_operators' => array( '=', 'IN' ) ),
 					// Duplicate-event discovery uses a title equality candidate set.
+					// MySQL's nonbinary VARCHAR comparisons ignore trailing spaces.
 					// Keep its file-backed scan bounded to ASCII comparisons instead
 					// of assuming MySQL's full Unicode collation.
 					'post_title' => array(
-						'normalizer'       => array( self::class, 'normalize_ascii_ci' ),
+						'normalizer'       => array( self::class, 'normalize_ascii_ci_padded' ),
 						'lookup_operators' => array( '=', 'IN' ),
 						'lookup_validator' => static fn( array $values ): bool => self::all_ascii_strings( $values ),
 					),
diff --git a/inc/native/class-wp-markdown-native-table-providers.php b/inc/native/class-wp-markdown-native-table-providers.php
index cb9b927..aed3822 100644
--- a/inc/native/class-wp-markdown-native-table-providers.php
+++ b/inc/native/class-wp-markdown-native-table-providers.php
@@ -235,6 +235,9 @@ protected function path_signature( string $path, ?string $content_digest = null
 }
 
 final class WP_Markdown_Native_Post_Provider extends WP_Markdown_Native_File_Provider {
+	// Exact title predicates do not have a file-addressable canonical index.
+	private const TITLE_LOOKUP_SOURCE_FILE_BUDGET = 1024;
+
 	private WP_Markdown_Storage $storage;
 	private WP_Markdown_Native_Post_Catalogue $catalogue;
 	/** @var array<string,array<int,array{post:object,row:array<string,mixed>,file:array<string,mixed>,identity:array<string,int>}>> */
@@ -331,6 +334,19 @@ private function post_type_scope( WP_Markdown_Native_Table_Access $access ): ?ar
 		return null;
 	}
 
+	/** Whether this read needs the bounded fallback scan for a title lookup. */
+	private function has_title_lookup( array $predicates ): bool {
+		foreach ( $predicates as $predicate ) {
+			if ( 'post_title' === $predicate->column()
+				&& in_array( $predicate->operator(), array( '=', 'IN' ), true )
+				&& $this->schema->allows_lookup( 'post_title', $predicate->operator(), $predicate->values() )
+			) {
+				return true;
+			}
+		}
+		return false;
+	}
+
 	/**
 	 * Resolve a read restricted to durable identity without walking the corpus.
 	 *
@@ -426,6 +442,8 @@ private function read_posts( WP_Markdown_Native_Table_Access $access, array $all
 					static fn( WP_Markdown_Native_Query_Predicate $predicate ): bool => ! in_array( 'post_content', $predicate->columns(), true )
 				)
 			);
+			$title_lookup = $this->has_title_lookup( $predicates );
+			$title_source_files = 0;
 			$scope = $this->post_type_scope( $access );
 			$key = null === $scope ? null : $this->parse_key( $scope );
 			$ordered = false;
@@ -444,6 +462,13 @@ private function read_posts( WP_Markdown_Native_Table_Access $access, array $all
 				$scanning = true;
 			}
 			foreach ( $this->storage->get_markdown_file_manifest_iterator( true, $scope ) as $file ) {
+				if ( $title_lookup && ++$title_source_files > self::TITLE_LOOKUP_SOURCE_FILE_BUDGET ) {
+					return $this->failure(
+						'markdown_db_native_source_work_budget',
+						'title_lookup_source_budget',
+						'mdi-native refuses title lookups that require scanning more than 1024 canonical files.'
+					);
+				}
 				// The manifest looked at this file to yield it, so its witness
 				// is the one taken then.
 				$witness = $file['witness'] ?? WP_Markdown_File_Witness::take( $file['absolute'] );
diff --git a/tests/smoke-native-like-query.php b/tests/smoke-native-like-query.php
index a3e9337..3aedeac 100644
--- a/tests/smoke-native-like-query.php
+++ b/tests/smoke-native-like-query.php
@@ -29,6 +29,8 @@
 $prefix = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title LIKE 'Good%'", 'wp_' ) );
 $ci = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title LIKE '%hello%'", 'wp_' ) );
 $exact = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title = 'hello world'", 'wp_' ) );
+$ordered_exact = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title = 'hello world' ORDER BY post_date_gmt DESC LIMIT 1", 'wp_' ) );
+$padded = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title = 'Hello World   '", 'wp_' ) );
 $candidates = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title IN ('goodbye moon', 'unrelated') ORDER BY ID", 'wp_' ) );
 $exact_unicode = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title = 'Café'", 'wp_' ) );
 $content_like = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_content LIKE '%hello%'", 'wp_' ) );
@@ -46,6 +48,8 @@
 	'a prefix-pattern matches ASCII titles' => array( '12' ) === $ids( $prefix ),
 	'LIKE matching is ASCII case-insensitive' => array( '11' ) === $ids( $ci ),
 	'an exact title lookup is ASCII case-insensitive' => array( '11' ) === $ids( $exact ),
+	'an ordered title lookup retains its LIMIT result' => array( '11' ) === $ids( $ordered_exact ),
+	'an exact title lookup ignores trailing spaces' => array( '11' ) === $ids( $padded ),
 	'a bounded title candidate set is indexable' => array( '12', '13' ) === $ids( $candidates ),
 	'a non-ASCII exact title lookup fails closed' => false === $exact_unicode->return_value()
 		&& 'unsupported_lookup' === ( $exact_unicode->diagnostic()['reason'] ?? null ),
diff --git a/tests/smoke-native-post-title-lookup-budget.php b/tests/smoke-native-post-title-lookup-budget.php
new file mode 100644
index 0000000..fb14702
--- /dev/null
+++ b/tests/smoke-native-post-title-lookup-budget.php
@@ -0,0 +1,37 @@
+<?php
+/** Exact title lookup source-work budget. */
+
+declare( strict_types=1 );
+
+define( 'ABSPATH', __DIR__ . '/' );
+require_once __DIR__ . '/../inc/native/class-wp-markdown-native-query-runtime.php';
+
+$root = sys_get_temp_dir() . '/mdi-native-title-budget-' . bin2hex( random_bytes( 6 ) );
+$state = $root . '/state';
+$content = $root . '/content';
+if ( ! mkdir( $state . '/_options', 0777, true ) || ! mkdir( $content . '/post', 0777, true ) ) {
+	throw new RuntimeException( 'Failed to create the title lookup budget fixture.' );
+}
+
+for ( $id = 1; $id <= 1025; $id++ ) {
+	file_put_contents(
+		$content . '/post/post-' . $id . '.md',
+		"---\nid: {$id}\ntitle: Other {$id}\nstatus: publish\ntype: post\nauthor: 1\ndate: 2026-08-27 12:00:00\nmodified: 2026-08-27 12:00:00\nslug: post-{$id}\ncomment_status: open\nping_status: open\n---\n\nBody\n"
+	);
+}
+
+$runtime = WP_Markdown_Native_Runtime_Factory::runtime( $state, 'wp_', null, false, $content );
+$result = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_title = 'Absent' ORDER BY post_date_gmt DESC LIMIT 1", 'wp_' ) );
+$passed = false === $result->return_value()
+	&& 'title_lookup_source_budget' === ( $result->diagnostic()['reason'] ?? null );
+
+echo ( $passed ? 'PASS' : 'FAIL' ) . ": title lookup stops after its explicit source-work budget\n";
+array_map( 'unlink', glob( $content . '/post/*' ) ?: array() );
+@rmdir( $content . '/post' );
+@rmdir( $content );
+array_map( 'unlink', glob( $state . '/_options/*' ) ?: array() );
+@rmdir( $state . '/_options' );
+@rmdir( $state );
+@rmdir( $root );
+
+exit( $passed ? 0 : 1 );

From f3c9768d2d0574ba294b62829dd72fda37f8d3e7 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 14:44:13 -0400
Subject: [PATCH 27/53] fix(native): migrate legacy multisite user snapshots

---
 ...ass-wp-markdown-native-table-providers.php | 24 ++++++++++++++++++-
 tests/smoke-native-generic-query.php          | 13 ++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/inc/native/class-wp-markdown-native-table-providers.php b/inc/native/class-wp-markdown-native-table-providers.php
index aed3822..6aa6aba 100644
--- a/inc/native/class-wp-markdown-native-table-providers.php
+++ b/inc/native/class-wp-markdown-native-table-providers.php
@@ -668,7 +668,29 @@ public function rows(): array|WP_Markdown_Query_Result {
 		$data = $this->read_json( $path, $root, 'table_file' );
 		return $this->snapshot = $data instanceof WP_Markdown_Query_Result
 			? $data
-			: $this->validate_rows( $data );
+			: $this->validate_rows( $this->materialize_multisite_user_defaults( $data ) );
+	}
+
+	/**
+	 * Older canonical user snapshots predate the two network-only columns.
+	 * MySQL supplies their declared zero defaults when a single-site snapshot is
+	 * opened by a multisite runtime, so preserve that durable representation.
+	 */
+	private function materialize_multisite_user_defaults( mixed $rows ): mixed {
+		if ( 'users.json' !== $this->filename
+			|| ! $this->schema->has_column( 'spam' )
+			|| ! $this->schema->has_column( 'deleted' )
+			|| ! is_array( $rows )
+			|| ! array_is_list( $rows )
+		) {
+			return $rows;
+		}
+		foreach ( $rows as $offset => $row ) {
+			if ( is_array( $row ) ) {
+				$rows[ $offset ] = array_merge( array( 'spam' => '0', 'deleted' => '0' ), $row );
+			}
+		}
+		return $rows;
 	}
 
 	/**
diff --git a/tests/smoke-native-generic-query.php b/tests/smoke-native-generic-query.php
index 76c5705..c0bd104 100644
--- a/tests/smoke-native-generic-query.php
+++ b/tests/smoke-native-generic-query.php
@@ -183,6 +183,13 @@ public function get_col_info( string $type ): array {
 $multisite_user['spam'] = '0';
 $multisite_user['deleted'] = '0';
 $multisite_schema = WP_Markdown_Native_Runtime_Factory::users_schema( true );
+$legacy_multisite_root = sys_get_temp_dir() . '/mdi-native-legacy-multisite-users-' . bin2hex( random_bytes( 6 ) );
+mkdir( $legacy_multisite_root . '/_tables', 0777, true );
+mkdir( $legacy_multisite_root . '/_options', 0777, true );
+file_put_contents( $legacy_multisite_root . '/_tables/users.json', json_encode( array( $users[1] ), JSON_THROW_ON_ERROR ) );
+$legacy_multisite_user = WP_Markdown_Native_Runtime_Factory::runtime( $legacy_multisite_root, 'wp_', 'wp_', true )->execute(
+	new WP_Markdown_Query_Request( "SELECT spam, deleted FROM wp_users WHERE user_login = 'admin'" )
+);
 
 $checks = array(
 	'native wpdb reports the semantics it implements without mysqli' => '8.0.0-mdi-native' === $database->db_server_info()
@@ -231,6 +238,8 @@ public function get_col_info( string $type ): array {
 		&& false === $invalid_width->return_value()
 		&& array() === $invalid_width->wpdb_state()['last_result'],
 	'multisite user schemas accept required spam and deleted columns' => true === $multisite_schema->validate_row( $multisite_user ),
+	'legacy single-site user snapshots receive multisite defaults' => '0' === ( $legacy_multisite_user->wpdb_state()['last_result'][0]->spam ?? null )
+		&& '0' === ( $legacy_multisite_user->wpdb_state()['last_result'][0]->deleted ?? null ),
 );
 
 $failed = 0;
@@ -246,4 +255,8 @@ public function get_col_info( string $type ): array {
 @rmdir( $root . '/_tables' );
 @rmdir( $root . '/_options' );
 @rmdir( $root );
+@unlink( $legacy_multisite_root . '/_tables/users.json' );
+@rmdir( $legacy_multisite_root . '/_tables' );
+@rmdir( $legacy_multisite_root . '/_options' );
+@rmdir( $legacy_multisite_root );
 exit( $failed ? 1 : 0 );

From a5b28d8b850c75194363e9429782d2754a9a101c Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 15:43:04 -0400
Subject: [PATCH 28/53] fix(native): support bounded not-equal table deletes

---
 ...wp-markdown-native-table-insert-parser.php |  5 +++--
 ...ass-wp-markdown-native-table-mutations.php |  4 ++++
 tests/smoke-native-table-write.php            | 21 +++++++++++++++++++
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-table-insert-parser.php b/inc/native/class-wp-markdown-native-table-insert-parser.php
index 37c8ade..76be948 100644
--- a/inc/native/class-wp-markdown-native-table-insert-parser.php
+++ b/inc/native/class-wp-markdown-native-table-insert-parser.php
@@ -268,12 +268,13 @@ private function where_factor() {
 		return new WP_Markdown_Native_Table_Predicate( $column, array( $value ), false );
 	}
 
-	/** @return '<'|'<='|'>'|'>='|null */
+	/** @return '<>'|'<'|'<='|'>'|'>='|null */
 	private function comparison_operator(): ?string {
 		$type = $this->current()->type();
-		if ( in_array( $type, array( WP_Markdown_Native_SQL_Token::LESS_THAN, WP_Markdown_Native_SQL_Token::LESS_EQUALS, WP_Markdown_Native_SQL_Token::GREATER_THAN, WP_Markdown_Native_SQL_Token::GREATER_EQUALS ), true ) ) {
+		if ( in_array( $type, array( WP_Markdown_Native_SQL_Token::NOT_EQUALS, WP_Markdown_Native_SQL_Token::LESS_THAN, WP_Markdown_Native_SQL_Token::LESS_EQUALS, WP_Markdown_Native_SQL_Token::GREATER_THAN, WP_Markdown_Native_SQL_Token::GREATER_EQUALS ), true ) ) {
 			++$this->position;
 			return match ( $type ) {
+				WP_Markdown_Native_SQL_Token::NOT_EQUALS => '<>',
 				WP_Markdown_Native_SQL_Token::LESS_THAN => '<',
 				WP_Markdown_Native_SQL_Token::LESS_EQUALS => '<=',
 				WP_Markdown_Native_SQL_Token::GREATER_THAN => '>',
diff --git a/inc/native/class-wp-markdown-native-table-mutations.php b/inc/native/class-wp-markdown-native-table-mutations.php
index e965915..eb0f8ab 100644
--- a/inc/native/class-wp-markdown-native-table-mutations.php
+++ b/inc/native/class-wp-markdown-native-table-mutations.php
@@ -702,6 +702,10 @@ private function restricts_predicate( array $row, $predicate, WP_Markdown_Native
 			return true;
 		}
 		$operator = $predicate->operator();
+		if ( '<>' === $operator ) {
+			// Like MySQL, comparisons against NULL are unknown rather than true.
+			return null !== $value && ! $schema->values_match( $predicate->column(), $value, $predicate->values()[0] ?? null );
+		}
 		if ( in_array( $operator, array( '<', '<=', '>', '>=' ), true ) ) {
 			// A comparison with NULL is unknown, which never restricts.
 			if ( null === $value ) {
diff --git a/tests/smoke-native-table-write.php b/tests/smoke-native-table-write.php
index 1a06fec..fc69754 100644
--- a/tests/smoke-native-table-write.php
+++ b/tests/smoke-native-table-write.php
@@ -64,6 +64,12 @@ public function remove_placeholder_escape( string $value ): string {
 		'wp_'
 	)
 );
+$runtime->execute(
+	new WP_Markdown_Query_Request(
+		'CREATE TABLE wp_cleanup_agents (id BIGINT NOT NULL AUTO_INCREMENT, label VARCHAR(60) NULL, PRIMARY KEY (id))',
+		'wp_'
+	)
+);
 $runtime->execute(
 	new WP_Markdown_Query_Request(
 		'CREATE TABLE wp_unique_jobs (id BIGINT NOT NULL AUTO_INCREMENT, scope VARCHAR(20) NULL, token VARCHAR(20) NULL, PRIMARY KEY (id), UNIQUE KEY scoped_token (scope, token(3)))',
@@ -105,6 +111,13 @@ public function remove_placeholder_escape( string $value ): string {
 ) as $insert ) {
 	$runtime->execute( new WP_Markdown_Query_Request( $insert, 'wp_' ) );
 }
+foreach ( array(
+	"INSERT INTO wp_cleanup_agents (label) VALUES ('first')",
+	"INSERT INTO wp_cleanup_agents (label) VALUES ('admin')",
+	"INSERT INTO wp_cleanup_agents (label) VALUES ('third')",
+) as $insert ) {
+	$runtime->execute( new WP_Markdown_Query_Request( $insert, 'wp_' ) );
+}
 $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_corrupt_jobs (token, state) VALUES ('first', 'pending')", 'wp_' ) );
 $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_corrupt_jobs (token, state) VALUES ('second', 'pending')", 'wp_' ) );
 $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_proof_jobs (token, state) VALUES ('first', 'pending')", 'wp_' ) );
@@ -148,6 +161,12 @@ function column_values( string $root, string $column, string $table = 'agents' )
 );
 $after_delete = column_values( $root, 'label' );
 
+// WordPress fixture cleanup retains its administrative row with this shape.
+$inequality_delete = $runtime->execute(
+	new WP_Markdown_Query_Request( 'DELETE FROM wp_cleanup_agents WHERE id != 2', 'wp_' )
+);
+$after_inequality_delete = column_values( $root, 'label', 'cleanup_agents' );
+
 // Serialized values carry semicolons, which must not read as a statement separator.
 $serialized = $runtime->execute(
 	new WP_Markdown_Query_Request(
@@ -256,6 +275,8 @@ function column_values( string $root, string $column, string $table = 'agents' )
 		&& 1 === $matches_new_null->return_value(),
 	'DELETE removes only the restricted rows' => 1 === $deleted->return_value()
 		&& array( 'null-target', 'second' ) === $after_delete,
+	'a not-equal DELETE retains only its selected row' => 2 === $inequality_delete->return_value()
+		&& array( 'admin' ) === $after_inequality_delete,
 	'a serialized value is not read as a statement separator' => 1 === $serialized->return_value()
 		&& 'a:1:{s:3:"key";i:42;}' === ( $serialized_rows[ count( $serialized_rows ) - 1 ]['label'] ?? null ),
 	'a semicolon inside a literal survives an update' => 1 === $semicolon_text->return_value(),

From afad2b7f558e09224ac37fcc17cde7c25d90f4e0 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 16:20:20 -0400
Subject: [PATCH 29/53] fix(native): implicitly commit table DDL

---
 inc/native/class-wp-markdown-native-schema-mutations.php | 8 ++++++++
 tests/smoke-native-create-table.php                      | 6 ++++++
 2 files changed, 14 insertions(+)

diff --git a/inc/native/class-wp-markdown-native-schema-mutations.php b/inc/native/class-wp-markdown-native-schema-mutations.php
index 211fbe6..0755c61 100644
--- a/inc/native/class-wp-markdown-native-schema-mutations.php
+++ b/inc/native/class-wp-markdown-native-schema-mutations.php
@@ -27,6 +27,14 @@ public function __construct(
 	}
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
+		// MySQL commits an open transaction before every table DDL statement.
+		// Otherwise a later rollback would erase a schema that MySQL retains.
+		if ( null !== $this->transactions ) {
+			$committed = $this->transactions->commit();
+			if ( true !== $committed ) {
+				return $this->failure( 'transaction_commit_failed', $committed );
+			}
+		}
 		$sql = trim( $request->sql() );
 		if ( str_ends_with( $sql, ';' ) ) {
 			$sql = rtrim( substr( $sql, 0, -1 ) );
diff --git a/tests/smoke-native-create-table.php b/tests/smoke-native-create-table.php
index b7a3e3a..58e040f 100644
--- a/tests/smoke-native-create-table.php
+++ b/tests/smoke-native-create-table.php
@@ -43,6 +43,10 @@ function mdi_native_create_remove_tree( string $root ): void {
 $duplicate = $runtime->execute( new WP_Markdown_Query_Request( $ddl ) );
 $injected = $runtime->execute( new WP_Markdown_Query_Request( $ddl . '; DROP TABLE wp_options' ) );
 $reloaded = WP_Markdown_Native_Runtime_Factory::runtime( $root )->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_plugin_events' ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'START TRANSACTION' ) );
+$transactional_ddl = $runtime->execute( new WP_Markdown_Query_Request( 'CREATE TABLE wp_ddl_commit (id bigint unsigned NOT NULL, PRIMARY KEY (id))' ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK' ) );
+$ddl_survives_rollback = WP_Markdown_Native_Runtime_Factory::runtime( $root )->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_ddl_commit' ) );
 
 $checks = array(
 	'generic CREATE TABLE returns the WordPress DDL success shape' => true === $created->return_value()
@@ -61,6 +65,8 @@ function mdi_native_create_remove_tree( string $root ): void {
 		&& 'unsupported_grammar' === ( $injected->diagnostic()['reason'] ?? null )
 		&& $ddl . ";\n" === file_get_contents( $root . '/_schema/plugin_events.sql' ),
 	'persisted definitions restore introspection after a cold reload' => 'event_key' === ( $reloaded->wpdb_state()['last_result'][0]->Field ?? null ),
+	'table DDL implicitly commits and survives a later rollback' => true === $transactional_ddl->return_value()
+		&& 'id' === ( $ddl_survives_rollback->wpdb_state()['last_result'][0]->Field ?? null ),
 );
 
 $failed = false;

From 548042c47efac724d13d25744765dbc65a851b20 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Wed, 9 Sep 2026 16:22:06 -0400
Subject: [PATCH 30/53] test(native): cover event date schema DDL

---
 tests/smoke-native-create-table.php | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/tests/smoke-native-create-table.php b/tests/smoke-native-create-table.php
index 58e040f..2422508 100644
--- a/tests/smoke-native-create-table.php
+++ b/tests/smoke-native-create-table.php
@@ -44,7 +44,16 @@ function mdi_native_create_remove_tree( string $root ): void {
 $injected = $runtime->execute( new WP_Markdown_Query_Request( $ddl . '; DROP TABLE wp_options' ) );
 $reloaded = WP_Markdown_Native_Runtime_Factory::runtime( $root )->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_plugin_events' ) );
 $runtime->execute( new WP_Markdown_Query_Request( 'START TRANSACTION' ) );
-$transactional_ddl = $runtime->execute( new WP_Markdown_Query_Request( 'CREATE TABLE wp_ddl_commit (id bigint unsigned NOT NULL, PRIMARY KEY (id))' ) );
+$transactional_ddl = $runtime->execute( new WP_Markdown_Query_Request( "CREATE TABLE wp_ddl_commit (\n"
+	. " id bigint unsigned NOT NULL,\n"
+	. " start_datetime datetime NOT NULL,\n"
+	. " end_datetime datetime DEFAULT NULL,\n"
+	. " post_status varchar(20) NOT NULL DEFAULT 'publish',\n"
+	. " PRIMARY KEY (id),\n"
+	. " KEY start_datetime (start_datetime),\n"
+	. " KEY end_datetime (end_datetime),\n"
+	. " KEY status_start (post_status, start_datetime)\n"
+	. ') ENGINE=InnoDB DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_520_ci' ) );
 $runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK' ) );
 $ddl_survives_rollback = WP_Markdown_Native_Runtime_Factory::runtime( $root )->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_ddl_commit' ) );
 

From e4a639b10892d498e95288de62e9a597644235b5 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 10:24:43 -0400
Subject: [PATCH 31/53] fix: ignore stale missing cached post paths

---
 inc/class-wp-markdown-storage.php      |  2 +-
 tests/smoke-parent-promotion-index.php | 36 ++++++++++++++++++++++++--
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/inc/class-wp-markdown-storage.php b/inc/class-wp-markdown-storage.php
index 742b893..5d7d372 100644
--- a/inc/class-wp-markdown-storage.php
+++ b/inc/class-wp-markdown-storage.php
@@ -819,7 +819,7 @@ private function safe_unlink( string $path ): bool {
 
 	/** Remove a cached post path only when it still carries that post's ID. */
 	private function safe_unlink_owned_by( string $path, int $post_id ): bool {
-		return $post_id === $this->extract_id_from_file( $path ) && $this->safe_unlink( $path );
+		return $this->existing_path_is_safe( $path ) && $post_id === $this->extract_id_from_file( $path ) && $this->safe_unlink( $path );
 	}
 
 	/**
diff --git a/tests/smoke-parent-promotion-index.php b/tests/smoke-parent-promotion-index.php
index 3b38578..c2d04a6 100644
--- a/tests/smoke-parent-promotion-index.php
+++ b/tests/smoke-parent-promotion-index.php
@@ -375,9 +375,41 @@ function write_leaf( string $path, int $id, string $slug, int $parent = 0 ): voi
 assert_eq( $storage->read_file( $tmp_root . '/wiki/original.md', true )->ID ?? null, 20, 'reused path retains its new owner' );
 
 // ---------------------------------------------------------------------------
-// Test 8 — a fresh write still wins over a stale duplicate during first scan
+// Test 8 — an externally removed cached path does not become a read warning
 // ---------------------------------------------------------------------------
-echo "\nTest 8: fresh writes remain canonical during initial duplicate cleanup\n";
+echo "\nTest 8: stale missing cached paths are ignored without parsing them\n";
+
+rm_rf( $tmp_root );
+write_leaf( $tmp_root . '/wiki/original.md', 10, 'original' );
+
+$storage = new WP_Markdown_Storage( $tmp_root, array() );
+assert_true( null !== $storage->read_post( 10 ), 'initial read completes the index for a removable path' );
+unlink( $tmp_root . '/wiki/original.md' );
+
+set_error_handler( static function ( int $severity, string $message ): never {
+	throw new ErrorException( $message, 0, $severity );
+} );
+try {
+	$written_path = $storage->write_post( (object) array(
+		'ID'           => 10,
+		'post_type'    => 'wiki',
+		'post_name'    => 'replacement',
+		'post_parent'  => 0,
+		'post_status'  => 'publish',
+		'post_title'   => 'Replacement',
+		'post_content' => 'replacement body',
+	) );
+	assert_eq( $written_path, $tmp_root . '/wiki/replacement.md', 'write ignores the stale missing path without a warning' );
+} catch ( ErrorException $exception ) {
+	assert_true( false, 'stale missing cached path emitted a warning: ' . $exception->getMessage() );
+} finally {
+	restore_error_handler();
+}
+
+// ---------------------------------------------------------------------------
+// Test 9 — a fresh write still wins over a stale duplicate during first scan
+// ---------------------------------------------------------------------------
+echo "\nTest 9: fresh writes remain canonical during initial duplicate cleanup\n";
 
 rm_rf( $tmp_root );
 write_leaf( $tmp_root . '/wiki/stale/fresh.md', 30, 'fresh' );

From bf1278863be241d53d51fb3fbd8d313ddbd7fd2e Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 10:45:19 -0400
Subject: [PATCH 32/53] fix(native): support LIMIT OFFSET queries

---
 inc/native/class-wp-markdown-native-query-parser.php | 2 ++
 tests/smoke-native-query-parser.php                  | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index b030a32..d488cdd 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -794,6 +794,8 @@ private function select( bool $nested ): WP_Markdown_Native_SQL_Select|WP_Markdo
 				if ( $limit_offset > PHP_INT_MAX - $limit ) {
 					throw new WP_Markdown_Native_SQL_Parse_Error( 'overflow_limit', $this->current()->sql_offset(), 'mdi-native cannot apply the requested LIMIT.' );
 				}
+			} elseif ( $this->match_keyword( 'OFFSET' ) ) {
+				$limit_offset = $this->integer( 'overflow_limit', 'mdi-native cannot apply the requested LIMIT.' );
 			}
 		}
 		$union = null;
diff --git a/tests/smoke-native-query-parser.php b/tests/smoke-native-query-parser.php
index 66b5c8e..42a0353 100644
--- a/tests/smoke-native-query-parser.php
+++ b/tests/smoke-native-query-parser.php
@@ -50,6 +50,8 @@
 $composite_order_plan = $composite_order_ast instanceof WP_Markdown_Native_SQL_Select ? $parser->lower( $composite_order_ast ) : $composite_order_ast;
 $found_rows_query_ast = $parser->parse_ast( 'SELECT FOUND_ROWS()' );
 $found_rows_query_plan = $found_rows_query_ast instanceof WP_Markdown_Native_SQL_Found_Rows ? $parser->lower( $found_rows_query_ast ) : $found_rows_query_ast;
+$limit_offset_ast = $parser->parse_ast( 'SELECT ID FROM wp_posts ORDER BY ID LIMIT 10 OFFSET 20' );
+$limit_offset_plan = $limit_offset_ast instanceof WP_Markdown_Native_SQL_Select ? $parser->lower( $limit_offset_ast ) : $limit_offset_ast;
 
 $duplicate_sql = 'SELECT first, second, first FROM example';
 $duplicate     = $parser->parse( $duplicate_sql );
@@ -189,6 +191,9 @@
 		),
 	'FOUND_ROWS lowers to explicit runtime state retrieval intent' => $found_rows_query_ast instanceof WP_Markdown_Native_SQL_Found_Rows
 		&& $found_rows_query_plan instanceof WP_Markdown_Native_Found_Rows_Plan,
+	'LIMIT OFFSET lowers to the bounded main-query offset' => $limit_offset_plan instanceof WP_Markdown_Native_Query_Plan
+		&& 10 === $limit_offset_plan->limit()
+		&& 20 === $limit_offset_plan->limit_offset(),
 	'duplicate projections report the duplicate source position' => $duplicate instanceof WP_Markdown_Query_Result
 		&& 'duplicate_projection' === ( $duplicate->diagnostic()['reason'] ?? null )
 		&& strrpos( $duplicate_sql, 'first' ) === ( $duplicate->diagnostic()['sql_offset'] ?? null ),

From 18d2351e2b79ba8a9c5bfa9d7f87b721197498bf Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 11:36:29 -0400
Subject: [PATCH 33/53] fix(native): restore temporary schema lifecycle

---
 ...ss-wp-markdown-native-schema-mutations.php | 64 +++++++++++++++----
 tests/smoke-native-create-table.php           | 11 ++++
 2 files changed, 62 insertions(+), 13 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-schema-mutations.php b/inc/native/class-wp-markdown-native-schema-mutations.php
index 0755c61..2651458 100644
--- a/inc/native/class-wp-markdown-native-schema-mutations.php
+++ b/inc/native/class-wp-markdown-native-schema-mutations.php
@@ -27,14 +27,6 @@ public function __construct(
 	}
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
-		// MySQL commits an open transaction before every table DDL statement.
-		// Otherwise a later rollback would erase a schema that MySQL retains.
-		if ( null !== $this->transactions ) {
-			$committed = $this->transactions->commit();
-			if ( true !== $committed ) {
-				return $this->failure( 'transaction_commit_failed', $committed );
-			}
-		}
 		$sql = trim( $request->sql() );
 		if ( str_ends_with( $sql, ';' ) ) {
 			$sql = rtrim( substr( $sql, 0, -1 ) );
@@ -42,6 +34,13 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		if ( '' === $sql || WP_Markdown_Native_SQL_Tokenizer::contains_statement_separator( $sql ) ) {
 			return $this->failure( 'unsupported_grammar', 'mdi-native requires one bounded CREATE TABLE statement.' );
 		}
+		// Unlike permanent DDL, CREATE TEMPORARY TABLE does not implicitly commit.
+		if ( null !== $this->transactions && 1 !== preg_match( '/^CREATE\s+TEMPORARY\s+TABLE\b/i', $sql ) ) {
+			$committed = $this->transactions->commit();
+			if ( true !== $committed ) {
+				return $this->failure( 'transaction_commit_failed', $committed );
+			}
+		}
 		if ( 1 === preg_match( '/^\s*ALTER\s+TABLE\b/i', $sql ) ) {
 			return $this->execute_alter( $request, $sql );
 		}
@@ -103,7 +102,7 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 					? WP_Markdown_Query_Result::schema_changed()
 					: $this->failure( 'table_exists', 'mdi-native cannot create a table that already exists.' );
 			}
-			$written = $this->write( $path, $sql . ";\n" );
+			$written = $this->write_schema( $path, $sql . ";\n", $table, $suffix, $request->table_prefix() );
 			if ( $written instanceof WP_Markdown_Query_Result ) {
 				return $written;
 			}
@@ -217,7 +216,7 @@ private function execute_alter( WP_Markdown_Query_Request $request, string $sql
 				return $reconciled;
 			}
 
-			$written = $this->write( $path, $rewritten );
+			$written = $this->write_schema( $path, $rewritten, $table, $suffix, $prefix );
 			if ( $written instanceof WP_Markdown_Query_Result ) {
 				return $written;
 			}
@@ -283,7 +282,7 @@ private function execute_drop( WP_Markdown_Query_Request $request, string $sql )
 			}
 			if ( is_file( $path ) && ! is_link( $path ) ) {
 				if ( null !== $this->transactions ) {
-					$recorded = $this->transactions->record( $path );
+					$recorded = $this->record_schema( $path, $table, $suffix, $prefix );
 					if ( true !== $recorded ) {
 						return $this->failure( 'transaction_journal_failed', $recorded );
 					}
@@ -398,7 +397,7 @@ private function execute_add_index( string $table, string $suffix, string $actio
 				} catch ( InvalidArgumentException ) {
 					return $this->failure( 'unsupported_schema', 'The altered table definition could not be compiled.' );
 				}
-				$written = $this->write( $path, $rewritten );
+				$written = $this->write_schema( $path, $rewritten, $table, $suffix, $this->table_prefix_from( $table, $suffix ) );
 				if ( $written instanceof WP_Markdown_Query_Result ) {
 					return $written;
 				}
@@ -488,7 +487,7 @@ private function execute_drop_index( string $table, string $suffix, string $name
 			}
 			$definition = $compiled[ $suffix ];
 			$schema = WP_Markdown_Native_Schema_Catalog::indexed_snapshot_schema( $definition );
-			$written = $this->write( $path, $rewritten );
+			$written = $this->write_schema( $path, $rewritten, $table, $suffix, $this->table_prefix_from( $table, $suffix ) );
 			if ( $written instanceof WP_Markdown_Query_Result ) {
 				return $written;
 			}
@@ -690,6 +689,41 @@ private function schema_directory(): string|WP_Markdown_Query_Result {
 		return $root;
 	}
 
+	private function write_schema( string $path, string $contents, string $table, string $suffix, string $prefix ): true|WP_Markdown_Query_Result {
+		$recorded = $this->record_schema( $path, $table, $suffix, $prefix );
+		if ( true !== $recorded ) {
+			return $this->failure( 'transaction_journal_failed', $recorded );
+		}
+		return $this->publish( $path, $contents );
+	}
+
+	/** Rebuild the registry after a transaction restores a schema pre-image. */
+	private function record_schema( string $path, string $table, string $suffix, string $prefix ): true|string {
+		return null === $this->transactions
+			? true
+			: $this->transactions->record( $path, function () use ( $path, $table, $suffix, $prefix ): void {
+				$this->registry->unregister( $table );
+				if ( ! is_file( $path ) || is_link( $path ) ) {
+					return;
+				}
+				try {
+					$definitions = WP_Markdown_Native_Schema_Catalog::compile( (string) file_get_contents( $path ), array( $prefix ) );
+					$definition = $definitions[ $suffix ] ?? null;
+					$schema = is_array( $definition ) ? WP_Markdown_Native_Schema_Catalog::indexed_snapshot_schema( $definition ) : null;
+				} catch ( InvalidArgumentException ) {
+					return;
+				}
+				if ( ! is_array( $definition ) ) {
+					return;
+				}
+				if ( null === $schema ) {
+					$this->registry->register_definition( $table, $definition );
+					return;
+				}
+				$this->registry->register( $table, $schema, new WP_Markdown_Native_JSON_Snapshot_Provider( $this->state_root, $schema, $suffix . '.json' ) );
+			} );
+	}
+
 	private function write( string $path, string $contents ): true|WP_Markdown_Query_Result {
 		if ( null !== $this->transactions ) {
 			$recorded = $this->transactions->record( $path );
@@ -697,6 +731,10 @@ private function write( string $path, string $contents ): true|WP_Markdown_Query
 				return $this->failure( 'transaction_journal_failed', $recorded );
 			}
 		}
+		return $this->publish( $path, $contents );
+	}
+
+	private function publish( string $path, string $contents ): true|WP_Markdown_Query_Result {
 		try {
 			$temp = $path . '.tmp-' . getmypid() . '-' . bin2hex( random_bytes( 8 ) );
 		} catch ( Throwable ) {
diff --git a/tests/smoke-native-create-table.php b/tests/smoke-native-create-table.php
index 2422508..7732b51 100644
--- a/tests/smoke-native-create-table.php
+++ b/tests/smoke-native-create-table.php
@@ -56,6 +56,13 @@ function mdi_native_create_remove_tree( string $root ): void {
 	. ') ENGINE=InnoDB DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_520_ci' ) );
 $runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK' ) );
 $ddl_survives_rollback = WP_Markdown_Native_Runtime_Factory::runtime( $root )->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_ddl_commit' ) );
+$temporary_ddl = 'CREATE TEMPORARY TABLE wp_ddl_temporary (id bigint unsigned NOT NULL, PRIMARY KEY (id))';
+$runtime->execute( new WP_Markdown_Query_Request( 'START TRANSACTION' ) );
+$temporary_created = $runtime->execute( new WP_Markdown_Query_Request( $temporary_ddl ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK' ) );
+$temporary_after_rollback = $runtime->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_ddl_temporary' ) );
+$temporary_schema_rolled_back = ! file_exists( $root . '/_schema/ddl_temporary.sql' );
+$temporary_recreated = $runtime->execute( new WP_Markdown_Query_Request( $temporary_ddl ) );
 
 $checks = array(
 	'generic CREATE TABLE returns the WordPress DDL success shape' => true === $created->return_value()
@@ -76,6 +83,10 @@ function mdi_native_create_remove_tree( string $root ): void {
 	'persisted definitions restore introspection after a cold reload' => 'event_key' === ( $reloaded->wpdb_state()['last_result'][0]->Field ?? null ),
 	'table DDL implicitly commits and survives a later rollback' => true === $transactional_ddl->return_value()
 		&& 'id' === ( $ddl_survives_rollback->wpdb_state()['last_result'][0]->Field ?? null ),
+	'temporary DDL remains transactional and does not leave a stale registry entry' => true === $temporary_created->return_value()
+		&& false === $temporary_after_rollback->return_value()
+		&& true === $temporary_recreated->return_value()
+		&& $temporary_schema_rolled_back,
 );
 
 $failed = false;

From 7d977b32720c918e4f1605c2a3195830683e49da Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 11:44:31 -0400
Subject: [PATCH 34/53] fix(native): preserve temporary DDL across rollback

---
 ...ss-wp-markdown-native-schema-mutations.php | 22 +++++++++++--------
 tests/smoke-native-create-table.php           | 18 ++++++++++-----
 2 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-schema-mutations.php b/inc/native/class-wp-markdown-native-schema-mutations.php
index 2651458..5b3f984 100644
--- a/inc/native/class-wp-markdown-native-schema-mutations.php
+++ b/inc/native/class-wp-markdown-native-schema-mutations.php
@@ -34,8 +34,9 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		if ( '' === $sql || WP_Markdown_Native_SQL_Tokenizer::contains_statement_separator( $sql ) ) {
 			return $this->failure( 'unsupported_grammar', 'mdi-native requires one bounded CREATE TABLE statement.' );
 		}
-		// Unlike permanent DDL, CREATE TEMPORARY TABLE does not implicitly commit.
-		if ( null !== $this->transactions && 1 !== preg_match( '/^CREATE\s+TEMPORARY\s+TABLE\b/i', $sql ) ) {
+		$temporary = 1 === preg_match( '/^(?:CREATE|DROP)\s+TEMPORARY\s+TABLE\b/i', $sql );
+		// Temporary table DDL neither commits nor participates in transaction rollback.
+		if ( null !== $this->transactions && ! $temporary ) {
 			$committed = $this->transactions->commit();
 			if ( true !== $committed ) {
 				return $this->failure( 'transaction_commit_failed', $committed );
@@ -102,7 +103,7 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 					? WP_Markdown_Query_Result::schema_changed()
 					: $this->failure( 'table_exists', 'mdi-native cannot create a table that already exists.' );
 			}
-			$written = $this->write_schema( $path, $sql . ";\n", $table, $suffix, $request->table_prefix() );
+			$written = $this->write_schema( $path, $sql . ";\n", $table, $suffix, $request->table_prefix(), $temporary );
 			if ( $written instanceof WP_Markdown_Query_Result ) {
 				return $written;
 			}
@@ -243,6 +244,7 @@ private function execute_drop( WP_Markdown_Query_Request $request, string $sql )
 		if ( 1 !== preg_match( '/^\s*DROP\s+(?:TEMPORARY\s+)?TABLE\s+(IF\s+EXISTS\s+)?`?([A-Za-z0-9_]+)`?\s*$/is', $sql, $matched ) ) {
 			return $this->failure( 'unsupported_schema', 'mdi-native supports one bounded DROP TABLE statement.' );
 		}
+		$temporary = 1 === preg_match( '/^\s*DROP\s+TEMPORARY\s+TABLE\b/i', $sql );
 		$tolerates_missing = '' !== trim( (string) $matched[1] );
 		$table = $matched[2];
 		$prefix = $request->table_prefix();
@@ -281,7 +283,7 @@ private function execute_drop( WP_Markdown_Query_Request $request, string $sql )
 					: $this->failure( 'unknown_table', 'mdi-native cannot drop a table it does not persist.' );
 			}
 			if ( is_file( $path ) && ! is_link( $path ) ) {
-				if ( null !== $this->transactions ) {
+				if ( null !== $this->transactions && ! $temporary ) {
 					$recorded = $this->record_schema( $path, $table, $suffix, $prefix );
 					if ( true !== $recorded ) {
 						return $this->failure( 'transaction_journal_failed', $recorded );
@@ -293,7 +295,7 @@ private function execute_drop( WP_Markdown_Query_Request $request, string $sql )
 			}
 			$snapshot = $this->state_root . '/_tables/' . $suffix . '.json';
 			if ( is_file( $snapshot ) && ! is_link( $snapshot ) ) {
-				if ( null !== $this->transactions ) {
+				if ( null !== $this->transactions && ! $temporary ) {
 					$recorded = $this->transactions->record( $snapshot );
 					if ( true !== $recorded ) {
 						return $this->failure( 'transaction_journal_failed', $recorded );
@@ -689,10 +691,12 @@ private function schema_directory(): string|WP_Markdown_Query_Result {
 		return $root;
 	}
 
-	private function write_schema( string $path, string $contents, string $table, string $suffix, string $prefix ): true|WP_Markdown_Query_Result {
-		$recorded = $this->record_schema( $path, $table, $suffix, $prefix );
-		if ( true !== $recorded ) {
-			return $this->failure( 'transaction_journal_failed', $recorded );
+	private function write_schema( string $path, string $contents, string $table, string $suffix, string $prefix, bool $temporary = false ): true|WP_Markdown_Query_Result {
+		if ( ! $temporary ) {
+			$recorded = $this->record_schema( $path, $table, $suffix, $prefix );
+			if ( true !== $recorded ) {
+				return $this->failure( 'transaction_journal_failed', $recorded );
+			}
 		}
 		return $this->publish( $path, $contents );
 	}
diff --git a/tests/smoke-native-create-table.php b/tests/smoke-native-create-table.php
index 7732b51..72e1312 100644
--- a/tests/smoke-native-create-table.php
+++ b/tests/smoke-native-create-table.php
@@ -59,10 +59,14 @@ function mdi_native_create_remove_tree( string $root ): void {
 $temporary_ddl = 'CREATE TEMPORARY TABLE wp_ddl_temporary (id bigint unsigned NOT NULL, PRIMARY KEY (id))';
 $runtime->execute( new WP_Markdown_Query_Request( 'START TRANSACTION' ) );
 $temporary_created = $runtime->execute( new WP_Markdown_Query_Request( $temporary_ddl ) );
+$temporary_inserted = $runtime->execute( new WP_Markdown_Query_Request( 'INSERT INTO wp_ddl_temporary (id) VALUES (1)' ) );
 $runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK' ) );
 $temporary_after_rollback = $runtime->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_ddl_temporary' ) );
-$temporary_schema_rolled_back = ! file_exists( $root . '/_schema/ddl_temporary.sql' );
-$temporary_recreated = $runtime->execute( new WP_Markdown_Query_Request( $temporary_ddl ) );
+$temporary_rows_after_rollback = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT id FROM wp_ddl_temporary' ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'START TRANSACTION' ) );
+$temporary_dropped = $runtime->execute( new WP_Markdown_Query_Request( 'DROP TEMPORARY TABLE wp_ddl_temporary' ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK' ) );
+$temporary_after_drop_rollback = $runtime->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_ddl_temporary' ) );
 
 $checks = array(
 	'generic CREATE TABLE returns the WordPress DDL success shape' => true === $created->return_value()
@@ -83,10 +87,12 @@ function mdi_native_create_remove_tree( string $root ): void {
 	'persisted definitions restore introspection after a cold reload' => 'event_key' === ( $reloaded->wpdb_state()['last_result'][0]->Field ?? null ),
 	'table DDL implicitly commits and survives a later rollback' => true === $transactional_ddl->return_value()
 		&& 'id' === ( $ddl_survives_rollback->wpdb_state()['last_result'][0]->Field ?? null ),
-	'temporary DDL remains transactional and does not leave a stale registry entry' => true === $temporary_created->return_value()
-		&& false === $temporary_after_rollback->return_value()
-		&& true === $temporary_recreated->return_value()
-		&& $temporary_schema_rolled_back,
+	'temporary table DDL survives rollback while its transactional rows roll back' => true === $temporary_created->return_value()
+		&& 1 === $temporary_inserted->wpdb_state()['rows_affected']
+		&& 'id' === ( $temporary_after_rollback->wpdb_state()['last_result'][0]->Field ?? null )
+		&& array() === $temporary_rows_after_rollback->wpdb_state()['last_result'],
+	'DROP TEMPORARY TABLE survives rollback and refreshes the table registry' => true === $temporary_dropped->return_value()
+		&& false === $temporary_after_drop_rollback->return_value(),
 );
 
 $failed = false;

From 66a20dc10c99469eaf34e020ae65cc242ee4e58d Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 12:04:07 -0400
Subject: [PATCH 35/53] fix(native): isolate temporary table generations

---
 ...class-wp-markdown-native-query-runtime.php |  6 +-
 .../class-wp-markdown-native-query-schema.php | 30 ++++++++
 ...ss-wp-markdown-native-schema-mutations.php | 54 ++++++++++----
 ...ass-wp-markdown-native-table-mutations.php | 74 ++++++++++++-------
 ...ss-wp-markdown-native-temporary-tables.php | 44 +++++++++++
 .../class-wp-markdown-native-transactions.php | 31 ++++++++
 tests/smoke-native-create-table.php           | 31 ++++++++
 7 files changed, 229 insertions(+), 41 deletions(-)
 create mode 100644 inc/native/class-wp-markdown-native-temporary-tables.php

diff --git a/inc/native/class-wp-markdown-native-query-runtime.php b/inc/native/class-wp-markdown-native-query-runtime.php
index a53b35d..90fc9df 100644
--- a/inc/native/class-wp-markdown-native-query-runtime.php
+++ b/inc/native/class-wp-markdown-native-query-runtime.php
@@ -23,6 +23,7 @@
 require_once __DIR__ . '/../class-wp-markdown-sql-classifier.php';
 require_once __DIR__ . '/../class-wp-markdown-table-durability-policy.php';
 require_once __DIR__ . '/class-wp-markdown-native-transactions.php';
+require_once __DIR__ . '/class-wp-markdown-native-temporary-tables.php';
 require_once __DIR__ . '/class-wp-markdown-native-advisory-locks.php';
 require_once __DIR__ . '/class-wp-markdown-native-query-executor.php';
 
@@ -269,6 +270,7 @@ public static function runtime(
 			array_filter( array( $state_root, $content_root, $global_state_root, $global_content_root ) )
 		);
 		$registry = self::registry( $state_root, $prefix, $base_prefix, $multisite, $content_root, $global_state_root, $global_content_root );
+		$temporary_tables = new WP_Markdown_Native_Temporary_Tables();
 		$parser = new WP_Markdown_Native_Table_Insert_Parser();
 		$resolved_base = $base_prefix ?? $prefix;
 		$resolved_content = $content_root ?? $state_root;
@@ -289,8 +291,8 @@ public static function runtime(
 			$registry,
 			new WP_Markdown_Native_Query_Parser(),
 			new WP_Markdown_Native_Option_Mutation_Runtime( $state_root, new WP_Markdown_Native_Option_Mutation_Parser(), $transactions ),
-			new WP_Markdown_Native_Schema_Mutation_Runtime( $state_root, $registry, $transactions, $core_registrar ),
-			new WP_Markdown_Native_Table_Mutation_Runtime( $state_root, $registry, $parser, $transactions ),
+			new WP_Markdown_Native_Schema_Mutation_Runtime( $state_root, $registry, $transactions, $core_registrar, $temporary_tables ),
+			new WP_Markdown_Native_Table_Mutation_Runtime( $state_root, $registry, $parser, $transactions, $temporary_tables ),
 			$transactions,
 			new WP_Markdown_Native_Post_Mutation_Runtime(
 				$registry,
diff --git a/inc/native/class-wp-markdown-native-query-schema.php b/inc/native/class-wp-markdown-native-query-schema.php
index 91e4f25..9a0d344 100644
--- a/inc/native/class-wp-markdown-native-query-schema.php
+++ b/inc/native/class-wp-markdown-native-query-schema.php
@@ -710,6 +710,8 @@ final class WP_Markdown_Native_Table_Registry {
 	private array $tables = array();
 	/** @var array<string,array<string,mixed>> */
 	private array $definitions = array();
+	/** @var array<string,array{table:?array{schema:WP_Markdown_Native_Table_Schema,provider:WP_Markdown_Native_Table_Provider},definition:?array<string,mixed>}> */
+	private array $shadows = array();
 
 	public function register(
 		string $table,
@@ -782,6 +784,34 @@ public function unregister( string $table ): void {
 		unset( $this->tables[ $table ], $this->definitions[ $table ] );
 	}
 
+	/** Replace a visible table for a connection-local temporary table. */
+	public function shadow( string $table, ?WP_Markdown_Native_Table_Schema $schema, ?WP_Markdown_Native_Table_Provider $provider, array $definition ): void {
+		if ( isset( $this->shadows[ $table ] ) ) {
+			throw new InvalidArgumentException( 'A temporary table already shadows this identifier.' );
+		}
+		$this->shadows[ $table ] = array( 'table' => $this->tables[ $table ] ?? null, 'definition' => $this->definitions[ $table ] ?? null );
+		unset( $this->tables[ $table ], $this->definitions[ $table ] );
+		$this->register_definition( $table, $definition );
+		if ( null !== $schema && null !== $provider ) {
+			$this->tables[ $table ] = array( 'schema' => $schema, 'provider' => $provider );
+		}
+	}
+
+	/** Restore the permanent table hidden by a dropped temporary table. */
+	public function unshadow( string $table ): void {
+		if ( ! isset( $this->shadows[ $table ] ) ) {
+			return;
+		}
+		$shadow = $this->shadows[ $table ];
+		unset( $this->tables[ $table ], $this->definitions[ $table ], $this->shadows[ $table ] );
+		if ( is_array( $shadow['definition'] ) ) {
+			$this->definitions[ $table ] = $shadow['definition'];
+		}
+		if ( is_array( $shadow['table'] ) ) {
+			$this->tables[ $table ] = $shadow['table'];
+		}
+	}
+
 	/** Forget request-scoped generic snapshots after canonical files are restored. */
 	public function forget_snapshots(): void {
 		foreach ( $this->tables as $table ) {
diff --git a/inc/native/class-wp-markdown-native-schema-mutations.php b/inc/native/class-wp-markdown-native-schema-mutations.php
index 5b3f984..3dddc1b 100644
--- a/inc/native/class-wp-markdown-native-schema-mutations.php
+++ b/inc/native/class-wp-markdown-native-schema-mutations.php
@@ -16,7 +16,8 @@ public function __construct(
 		string $state_root,
 		private WP_Markdown_Native_Table_Registry $registry,
 		private ?WP_Markdown_Native_Transaction_Journal $transactions = null,
-		?callable $core_registrar = null
+		?callable $core_registrar = null,
+		private ?WP_Markdown_Native_Temporary_Tables $temporary_tables = null
 	) {
 		$this->core_registrar = $core_registrar;
 		$root = realpath( $state_root );
@@ -66,25 +67,29 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		$definition = $definitions[ $suffix ];
 		// IF NOT EXISTS makes an existing table a successful no-op in MySQL.
 		$tolerates_existing = 1 === preg_match( '/^\s*CREATE\s+(?:TEMPORARY\s+)?TABLE\s+IF\s+NOT\s+EXISTS\b/i', $sql );
-		if ( null !== $this->registry->definition( $table ) ) {
+		if ( $temporary && null !== $this->temporary_tables && $this->temporary_tables->has( $table ) ) {
 			return $tolerates_existing
 				? WP_Markdown_Query_Result::schema_changed()
 				: $this->failure( 'table_exists', 'mdi-native cannot create a table that already exists.' );
 		}
+		if ( ! $temporary && null !== $this->registry->definition( $table ) ) {
+			return $tolerates_existing ? WP_Markdown_Query_Result::schema_changed() : $this->failure( 'table_exists', 'mdi-native cannot create a table that already exists.' );
+		}
 
 		// A core table is generated from WordPress itself, so creating it
 		// registers its canonical provider rather than persisting a schema
 		// file that would shadow the definition core already supplies. The
 		// name identifies it, because the release being installed states its
 		// own column list and that varies independently of canonical form.
-		if ( WP_Markdown_Native_Schema_Catalog::is_core_table( $suffix ) ) {
+		if ( ! $temporary && WP_Markdown_Native_Schema_Catalog::is_core_table( $suffix ) ) {
 			if ( null === $this->core_registrar || true !== ( $this->core_registrar )( $suffix ) ) {
 				return $this->failure( 'unsupported_schema', 'mdi-native cannot create the requested core table.' );
 			}
 			return WP_Markdown_Query_Result::schema_changed();
 		}
 
-		$directory = $this->schema_directory();
+		$root = $temporary && null !== $this->temporary_tables ? $this->temporary_tables->root() : $this->state_root;
+		$directory = $this->schema_directory( $root );
 		if ( $directory instanceof WP_Markdown_Query_Result ) {
 			return $directory;
 		}
@@ -98,7 +103,7 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 
 		try {
 			$path = $directory . '/' . $suffix . '.sql';
-			if ( file_exists( $path ) || is_link( $path ) || null !== $this->registry->definition( $table ) ) {
+			if ( file_exists( $path ) || is_link( $path ) || ( ! $temporary && null !== $this->registry->definition( $table ) ) ) {
 				return $tolerates_existing
 					? WP_Markdown_Query_Result::schema_changed()
 					: $this->failure( 'table_exists', 'mdi-native cannot create a table that already exists.' );
@@ -112,14 +117,17 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 			} catch ( InvalidArgumentException ) {
 				return $this->failure( 'unsupported_schema', 'mdi-native cannot compile the requested table definition.' );
 			}
-			if ( null === $schema ) {
+			if ( $temporary && null !== $this->temporary_tables ) {
+				if ( null === $schema ) {
+					$this->registry->shadow( $table, null, null, $definition );
+				} else {
+					$this->registry->shadow( $table, $schema, new WP_Markdown_Native_JSON_Snapshot_Provider( $root, $schema, $suffix . '.json' ), $definition );
+				}
+				$this->temporary_tables->add( $table );
+			} elseif ( null === $schema ) {
 				$this->registry->register_definition( $table, $definition );
 			} else {
-				$this->registry->register(
-					$table,
-					$schema,
-					new WP_Markdown_Native_JSON_Snapshot_Provider( $this->state_root, $schema, $suffix . '.json' )
-				);
+				$this->registry->register( $table, $schema, new WP_Markdown_Native_JSON_Snapshot_Provider( $root, $schema, $suffix . '.json' ) );
 			}
 			return WP_Markdown_Query_Result::schema_changed();
 		} finally {
@@ -261,6 +269,23 @@ private function execute_drop( WP_Markdown_Query_Request $request, string $sql )
 		if ( isset( WP_Markdown_Native_Schema_Catalog::definitions()[ $suffix ] ) ) {
 			return $this->failure( 'unsupported_schema', 'mdi-native cannot drop a core table.' );
 		}
+		if ( $temporary ) {
+			if ( null === $this->temporary_tables || ! $this->temporary_tables->has( $table ) ) {
+				return $tolerates_missing ? WP_Markdown_Query_Result::schema_changed() : $this->failure( 'unknown_table', 'mdi-native cannot drop a temporary table that does not exist.' );
+			}
+			$root = $this->temporary_tables->root();
+			if ( null !== $this->transactions ) {
+				$this->transactions->discard_ephemeral( $root . '/_tables/' . $suffix . '.json' );
+			}
+			@unlink( $root . '/_schema/' . $suffix . '.sql' );
+			@unlink( $root . '/_tables/' . $suffix . '.json' );
+			$this->temporary_tables->remove( $table );
+			$this->registry->unshadow( $table );
+			return WP_Markdown_Query_Result::schema_changed();
+		}
+		if ( null !== $this->temporary_tables && $this->temporary_tables->has( $table ) ) {
+			return $this->failure( 'temporary_table_shadowed', 'mdi-native cannot safely apply permanent DDL while a temporary table shadows that name.' );
+		}
 
 		$directory = $this->schema_directory();
 		if ( $directory instanceof WP_Markdown_Query_Result ) {
@@ -679,13 +704,14 @@ private function matching_paren( string $sql, int $open ): ?int {
 		return null;
 	}
 
-	private function schema_directory(): string|WP_Markdown_Query_Result {
-		$path = $this->state_root . '/_schema';
+	private function schema_directory( ?string $root = null ): string|WP_Markdown_Query_Result {
+		$base_root = $root ?? $this->state_root;
+		$path = $base_root . '/_schema';
 		if ( ! file_exists( $path ) && ! @mkdir( $path, 0755 ) && ! is_dir( $path ) ) {
 			return $this->failure( 'schema_directory_failed', 'The canonical schema directory could not be created.' );
 		}
 		$root = realpath( $path );
-		if ( false === $root || ! is_dir( $root ) || is_link( $path ) || dirname( $root ) !== $this->state_root ) {
+		if ( false === $root || ! is_dir( $root ) || is_link( $path ) || dirname( $root ) !== $base_root ) {
 			return $this->failure( 'unsafe_schema_directory', 'The canonical schema directory is unavailable or unsafe.' );
 		}
 		return $root;
diff --git a/inc/native/class-wp-markdown-native-table-mutations.php b/inc/native/class-wp-markdown-native-table-mutations.php
index eb0f8ab..afcc90a 100644
--- a/inc/native/class-wp-markdown-native-table-mutations.php
+++ b/inc/native/class-wp-markdown-native-table-mutations.php
@@ -11,6 +11,8 @@
 final class WP_Markdown_Native_Table_Mutation_Runtime {
 	private string $state_root;
 	private WP_Markdown_Native_Table_Index $index;
+	/** @var array<string,WP_Markdown_Native_Table_Index> */
+	private array $temporary_indexes = array();
 	/** @var array<string,WP_Markdown_File_Witness> */
 	private array $unique_sets_verified = array();
 
@@ -18,7 +20,8 @@ public function __construct(
 		string $state_root,
 		private WP_Markdown_Native_Table_Registry $registry,
 		private WP_Markdown_Native_Table_Insert_Parser $parser = new WP_Markdown_Native_Table_Insert_Parser(),
-		private ?WP_Markdown_Native_Transaction_Journal $transactions = null
+		private ?WP_Markdown_Native_Transaction_Journal $transactions = null,
+		private ?WP_Markdown_Native_Temporary_Tables $temporary_tables = null
 	) {
 		$root = realpath( $state_root );
 		if ( false === $root || ! is_dir( $root ) ) {
@@ -91,12 +94,13 @@ private function execute_insert( WP_Markdown_Query_Request $request, WP_Markdown
 			|| null === $table
 			|| ! $table['provider'] instanceof WP_Markdown_Native_JSON_Snapshot_Provider
 			|| ! is_array( $definition )
-			|| ! $this->is_authoritative_definition( $suffix, $definition, $prefix )
+			|| ! $this->is_authoritative_definition( $suffix, $definition, $prefix, $insert->table() )
 		) {
 			return $this->failure( 'unsupported_mutation_table', 'mdi-native can insert only into a persisted generic snapshot table.' );
 		}
 
-		$directory = $this->tables_directory();
+		$root = $this->root_for( $insert->table() );
+		$directory = $this->tables_directory( $root );
 		if ( $directory instanceof WP_Markdown_Query_Result ) {
 			return $directory;
 		}
@@ -124,9 +128,10 @@ private function execute_insert( WP_Markdown_Query_Request $request, WP_Markdown
 				}
 			}
 			$path = $directory . '/' . $suffix . '.json';
+			$table_index = $this->index_for( $root );
 			$index = $insert->is_replace() || null !== $insert->upsert_columns() || WP_Markdown_Native_Table_Index::supplies_identity( $insert->values(), $definition )
 				? null
-				: $this->index->load( $suffix, $path );
+				: $table_index->load( $suffix, $path );
 			if ( null !== $index ) {
 				// The index enforces this candidate's keys, while this witnessed
 				// snapshot proves the pre-existing keys were already unique.
@@ -152,7 +157,7 @@ private function execute_insert( WP_Markdown_Query_Request $request, WP_Markdown
 				if ( $appended instanceof WP_Markdown_Query_Result ) {
 					return $appended;
 				}
-				$this->index->remember( $suffix, $path, WP_Markdown_Native_Table_Index::with_row( $index, $row, $definition, $schema ) );
+				$table_index->remember( $suffix, $path, WP_Markdown_Native_Table_Index::with_row( $index, $row, $definition, $schema ) );
 				if ( $unique_set_verified ) {
 					$this->remember_verified_unique_set( $suffix, $path );
 				}
@@ -189,7 +194,7 @@ private function execute_insert( WP_Markdown_Query_Request $request, WP_Markdown
 					}
 					// REPLACE already scans and republishes the snapshot. Leave the
 					// derived insert index for the next operation that needs it.
-					$this->index->forget( $suffix, $this->transactions );
+					$table_index->forget( $suffix, $this->transactions );
 					$provider->replace_rows( $rows );
 					return WP_Markdown_Query_Result::mutated( count( $duplicates ) + 1, $this->auto_increment_value( $row, $definition ) );
 				}
@@ -218,7 +223,7 @@ private function execute_insert( WP_Markdown_Query_Request $request, WP_Markdown
 				if ( $written instanceof WP_Markdown_Query_Result ) {
 					return $written;
 				}
-				$this->index->save( $suffix, $path, WP_Markdown_Native_Table_Index::build( array_values( $rows ), $definition, $schema ), $this->transactions );
+				$table_index->save( $suffix, $path, WP_Markdown_Native_Table_Index::build( array_values( $rows ), $definition, $schema ), $this->transactions );
 				$provider->replace_rows( array_values( $rows ) );
 				return WP_Markdown_Query_Result::mutated( 2, $this->auto_increment_value( $updated, $definition ) );
 			}
@@ -227,7 +232,7 @@ private function execute_insert( WP_Markdown_Query_Request $request, WP_Markdown
 			if ( $written instanceof WP_Markdown_Query_Result ) {
 				return $written;
 			}
-			$this->index->save( $suffix, $path, WP_Markdown_Native_Table_Index::build( $rows, $definition, $schema ), $this->transactions );
+			$table_index->save( $suffix, $path, WP_Markdown_Native_Table_Index::build( $rows, $definition, $schema ), $this->transactions );
 			$provider->replace_rows( $rows );
 			return WP_Markdown_Query_Result::mutated( 1, $this->auto_increment_value( $row, $definition ) );
 		} finally {
@@ -269,7 +274,7 @@ private function append_row( string $path, array $row, bool $empty ): true|WP_Ma
 			return $this->failure( 'unsafe_table_file', 'The canonical table file is unavailable or unsafe.' );
 		}
 		if ( null !== $this->transactions ) {
-			$recorded = $this->transactions->record( $path );
+			$recorded = $this->is_temporary_path( $path ) ? $this->transactions->record_ephemeral( $path ) : $this->transactions->record( $path );
 			if ( true !== $recorded ) {
 				return $this->failure( 'transaction_journal_failed', $recorded );
 			}
@@ -462,7 +467,7 @@ private function execute_write( WP_Markdown_Query_Request $request ): WP_Markdow
 			|| null === $table
 			|| ! $table['provider'] instanceof WP_Markdown_Native_JSON_Snapshot_Provider
 			|| ! is_array( $definition )
-			|| ! $this->is_authoritative_definition( $suffix, $definition, $prefix )
+			|| ! $this->is_authoritative_definition( $suffix, $definition, $prefix, $write->table() )
 		) {
 			return $this->failure( 'unsupported_mutation_table', 'mdi-native can mutate only a persisted generic snapshot table.' );
 		}
@@ -487,7 +492,8 @@ private function execute_write( WP_Markdown_Query_Request $request ): WP_Markdow
 				return $this->failure( 'unsupported_mutation_column', 'The assignment names a column outside the persisted table schema.' );
 			}
 		}
-		$directory = $this->tables_directory();
+		$root = $this->root_for( $write->table() );
+		$directory = $this->tables_directory( $root );
 		if ( $directory instanceof WP_Markdown_Query_Result ) {
 			return $directory;
 		}
@@ -499,7 +505,8 @@ private function execute_write( WP_Markdown_Query_Request $request ): WP_Markdow
 		try {
 			$path = $directory . '/' . $suffix . '.json';
 			$provider = $table['provider'];
-			$index = $this->index->load( $suffix, $path );
+			$table_index = $this->index_for( $root );
+			$index = $table_index->load( $suffix, $path );
 			if ( null !== $index && $this->index_excludes( $index, $predicates ) ) {
 				return WP_Markdown_Query_Result::mutated( 0 );
 			}
@@ -533,7 +540,7 @@ private function execute_write( WP_Markdown_Query_Request $request ): WP_Markdow
 			}
 
 			if ( 0 === $affected ) {
-				$this->index->remember( $suffix, $path, WP_Markdown_Native_Table_Index::build( $rows, $definition, $schema ) );
+				$table_index->remember( $suffix, $path, WP_Markdown_Native_Table_Index::build( $rows, $definition, $schema ) );
 				return WP_Markdown_Query_Result::mutated( 0 );
 			}
 			$unique_set_verified = $write->is_update()
@@ -552,7 +559,7 @@ private function execute_write( WP_Markdown_Query_Request $request ): WP_Markdow
 			$this->remember_verified_unique_set( $suffix, $path );
 			// The sidecar is derived state. Keep this runtime's witnessed index
 			// current without republishing it after every canonical table write.
-			$this->index->remember( $suffix, $path, $updated_index ?? WP_Markdown_Native_Table_Index::build( $retained, $definition, $schema ) );
+			$table_index->remember( $suffix, $path, $updated_index ?? WP_Markdown_Native_Table_Index::build( $retained, $definition, $schema ) );
 			$provider->replace_rows( $retained );
 			return WP_Markdown_Query_Result::mutated( $affected );
 		} finally {
@@ -887,8 +894,8 @@ private function unique_set_violation( array $rows, array $definition, WP_Markdo
 	 *
 	 * @param array<string,mixed> $definition
 	 */
-	private function is_authoritative_definition( string $suffix, array $definition, string $prefix ): bool {
-		return $this->is_persisted_definition( $suffix, $definition, $prefix )
+	private function is_authoritative_definition( string $suffix, array $definition, string $prefix, string $table ): bool {
+		return $this->is_persisted_definition( $suffix, $definition, $prefix, $this->root_for( $table ) )
 			|| $this->is_generated_core_definition( $suffix, $definition );
 	}
 
@@ -897,10 +904,10 @@ private function is_generated_core_definition( string $suffix, array $definition
 		return WP_Markdown_Native_Schema_Catalog::is_generated_core_definition( $suffix, $definition );
 	}
 
-	private function is_persisted_definition( string $suffix, array $definition, string $prefix ): bool {
-		$directory = realpath( $this->state_root . '/_schema' );
+	private function is_persisted_definition( string $suffix, array $definition, string $prefix, string $root ): bool {
+		$directory = realpath( $root . '/_schema' );
 		$path = false === $directory ? '' : $directory . '/' . $suffix . '.sql';
-		if ( false === $directory || is_link( $this->state_root . '/_schema' ) || ! is_file( $path ) || is_link( $path ) ) {
+		if ( false === $directory || is_link( $root . '/_schema' ) || ! is_file( $path ) || is_link( $path ) ) {
 			return false;
 		}
 		try {
@@ -911,16 +918,16 @@ private function is_persisted_definition( string $suffix, array $definition, str
 		}
 	}
 
-	private function tables_directory(): string|WP_Markdown_Query_Result {
-		$path = $this->state_root . '/_tables';
+	private function tables_directory( string $root ): string|WP_Markdown_Query_Result {
+		$path = $root . '/_tables';
 		if ( ! file_exists( $path ) && ! @mkdir( $path, 0755 ) && ! is_dir( $path ) ) {
 			return $this->failure( 'tables_directory_failed', 'The canonical tables directory could not be created.' );
 		}
-		$root = realpath( $path );
-		if ( false === $root || ! is_dir( $root ) || is_link( $path ) || dirname( $root ) !== $this->state_root ) {
+		$directory = realpath( $path );
+		if ( false === $directory || ! is_dir( $directory ) || is_link( $path ) || dirname( $directory ) !== $root ) {
 			return $this->failure( 'unsafe_tables_directory', 'The canonical tables directory is unavailable or unsafe.' );
 		}
-		return $root;
+		return $directory;
 	}
 
 	/** Coordinate only writers that publish the same canonical table. */
@@ -942,7 +949,7 @@ private function write( string $path, array $rows ): true|WP_Markdown_Query_Resu
 			return $this->failure( 'unsafe_table_file', 'The canonical table file is unavailable or unsafe.' );
 		}
 		if ( null !== $this->transactions ) {
-			$recorded = $this->transactions->record( $path );
+			$recorded = $this->is_temporary_path( $path ) ? $this->transactions->record_ephemeral( $path ) : $this->transactions->record( $path );
 			if ( true !== $recorded ) {
 				return $this->failure( 'transaction_journal_failed', $recorded );
 			}
@@ -986,6 +993,23 @@ private function write( string $path, array $rows ): true|WP_Markdown_Query_Resu
 		return true;
 	}
 
+	private function root_for( string $table ): string {
+		return null !== $this->temporary_tables && $this->temporary_tables->has( $table )
+			? $this->temporary_tables->root()
+			: $this->state_root;
+	}
+
+	private function index_for( string $root ): WP_Markdown_Native_Table_Index {
+		if ( $root === $this->state_root ) {
+			return $this->index;
+		}
+		return $this->temporary_indexes[ $root ] ??= new WP_Markdown_Native_Table_Index( $root . DIRECTORY_SEPARATOR . '_tables' );
+	}
+
+	private function is_temporary_path( string $path ): bool {
+		return null !== $this->temporary_tables && str_starts_with( $path, $this->temporary_tables->root() . DIRECTORY_SEPARATOR );
+	}
+
 	private function failure( string $reason, string $message ): WP_Markdown_Query_Result {
 		return WP_Markdown_Query_Result::failure(
 			array(
diff --git a/inc/native/class-wp-markdown-native-temporary-tables.php b/inc/native/class-wp-markdown-native-temporary-tables.php
new file mode 100644
index 0000000..d47a11c
--- /dev/null
+++ b/inc/native/class-wp-markdown-native-temporary-tables.php
@@ -0,0 +1,44 @@
+<?php
+/** Per-runtime storage and catalog state for connection-scoped temporary tables. */
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+final class WP_Markdown_Native_Temporary_Tables {
+	private string $root;
+	/** @var array<string,true> */
+	private array $tables = array();
+
+	public function __construct() {
+		try {
+			$this->root = sys_get_temp_dir() . '/mdi-native-session-' . bin2hex( random_bytes( 16 ) );
+		} catch ( Throwable ) {
+			throw new RuntimeException( 'A temporary table namespace could not be created.' );
+		}
+		if ( ! @mkdir( $this->root . '/_schema', 0700, true ) || ! @mkdir( $this->root . '/_tables', 0700, true ) ) {
+			throw new RuntimeException( 'A temporary table namespace could not be materialized.' );
+		}
+		$root = realpath( $this->root );
+		if ( false === $root || is_link( $this->root ) ) {
+			throw new RuntimeException( 'A temporary table namespace is unsafe.' );
+		}
+		$this->root = $root;
+	}
+
+	public function root(): string {
+		return $this->root;
+	}
+
+	public function has( string $table ): bool {
+		return isset( $this->tables[ $table ] );
+	}
+
+	public function add( string $table ): void {
+		$this->tables[ $table ] = true;
+	}
+
+	public function remove( string $table ): void {
+		unset( $this->tables[ $table ] );
+	}
+}
diff --git a/inc/native/class-wp-markdown-native-transactions.php b/inc/native/class-wp-markdown-native-transactions.php
index 3b7ba8f..d8e88ec 100644
--- a/inc/native/class-wp-markdown-native-transactions.php
+++ b/inc/native/class-wp-markdown-native-transactions.php
@@ -345,6 +345,37 @@ public function record( string $path, ?callable $restore_observer = null ): true
 		return $this->persist();
 	}
 
+	/** Record a session-local pre-image without serializing it into the durable journal. */
+	public function record_ephemeral( string $path, ?callable $restore_observer = null ): true|string {
+		if ( ! $this->active ) {
+			return true;
+		}
+		if ( null !== $restore_observer ) {
+			$this->restore_observers[ $path ] = $restore_observer;
+		}
+		foreach ( $this->entries as $entry ) {
+			if ( $path === $entry['path'] ) {
+				return true;
+			}
+		}
+		$contents = is_file( $path ) ? @file_get_contents( $path ) : false;
+		if ( is_file( $path ) && false === $contents ) {
+			return 'The temporary table pre-image could not be journaled.';
+		}
+		$this->entries[] = array( 'path' => $path, 'existed' => false !== $contents, 'contents' => false === $contents ? null : base64_encode( $contents ) );
+		return true;
+	}
+
+	/** A dropped temporary table ends its generation, so old row pre-images are invalid. */
+	public function discard_ephemeral( string $path ): void {
+		$this->entries = array_values( array_filter( $this->entries, static fn( array $entry ): bool => $path !== $entry['path'] ) );
+		foreach ( array_keys( $this->restore_observers ) as $observed_path ) {
+			if ( $observed_path === $path ) {
+				unset( $this->restore_observers[ $observed_path ] );
+			}
+		}
+	}
+
 	/** Start an autocommit-off transaction when a transactional table is read. */
 	public function access(): true|string {
 		return ! $this->active && ! $this->autocommit ? $this->begin() : true;
diff --git a/tests/smoke-native-create-table.php b/tests/smoke-native-create-table.php
index 72e1312..02bb257 100644
--- a/tests/smoke-native-create-table.php
+++ b/tests/smoke-native-create-table.php
@@ -67,6 +67,27 @@ function mdi_native_create_remove_tree( string $root ): void {
 $temporary_dropped = $runtime->execute( new WP_Markdown_Query_Request( 'DROP TEMPORARY TABLE wp_ddl_temporary' ) );
 $runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK' ) );
 $temporary_after_drop_rollback = $runtime->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_ddl_temporary' ) );
+$permanent_only_drop = $runtime->execute( new WP_Markdown_Query_Request( 'DROP TEMPORARY TABLE wp_ddl_commit' ) );
+$permanent_only_drop_if_exists = $runtime->execute( new WP_Markdown_Query_Request( 'DROP TEMPORARY TABLE IF EXISTS wp_ddl_commit' ) );
+$permanent_after_temporary_drop = $runtime->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_ddl_commit' ) );
+
+$generation_ddl = 'CREATE TEMPORARY TABLE wp_temporary_generation (id bigint unsigned NOT NULL, PRIMARY KEY (id))';
+$runtime->execute( new WP_Markdown_Query_Request( $generation_ddl ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'INSERT INTO wp_temporary_generation (id) VALUES (1)' ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'START TRANSACTION' ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'UPDATE wp_temporary_generation SET id = 3 WHERE id = 1' ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'DROP TEMPORARY TABLE wp_temporary_generation' ) );
+$runtime->execute( new WP_Markdown_Query_Request( $generation_ddl ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK' ) );
+$generation_after_rollback = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT id FROM wp_temporary_generation' ) );
+
+$runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_plugin_events (event_key, owner_id, payload) VALUES ('permanent', 7, 'safe')" ) );
+$shadow_created = $runtime->execute( new WP_Markdown_Query_Request( 'CREATE TEMPORARY TABLE wp_plugin_events (id bigint unsigned NOT NULL, PRIMARY KEY (id))' ) );
+$shadow_inserted = $runtime->execute( new WP_Markdown_Query_Request( 'INSERT INTO wp_plugin_events (id) VALUES (9)' ) );
+$shadow_rows = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT id FROM wp_plugin_events' ) );
+$shadow_dropped = $runtime->execute( new WP_Markdown_Query_Request( 'DROP TEMPORARY TABLE wp_plugin_events' ) );
+$permanent_rows_after_shadow = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT event_key, owner_id, payload FROM wp_plugin_events' ) );
+$cold_temporary = WP_Markdown_Native_Runtime_Factory::runtime( $root )->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_temporary_generation' ) );
 
 $checks = array(
 	'generic CREATE TABLE returns the WordPress DDL success shape' => true === $created->return_value()
@@ -93,6 +114,16 @@ function mdi_native_create_remove_tree( string $root ): void {
 		&& array() === $temporary_rows_after_rollback->wpdb_state()['last_result'],
 	'DROP TEMPORARY TABLE survives rollback and refreshes the table registry' => true === $temporary_dropped->return_value()
 		&& false === $temporary_after_drop_rollback->return_value(),
+	'DROP TEMPORARY TABLE refuses a permanent-only name without touching its schema' => false === $permanent_only_drop->return_value()
+		&& true === $permanent_only_drop_if_exists->return_value()
+		&& 'id' === ( $permanent_after_temporary_drop->wpdb_state()['last_result'][0]->Field ?? null ),
+	'a dropped temporary generation cannot restore its old transactional row journal into a recreated table' => array() === $generation_after_rollback->wpdb_state()['last_result'],
+	'temporary tables shadow same-name permanent tables without overwriting their data and are absent from a cold runtime' => true === $shadow_created->return_value()
+		&& 1 === $shadow_inserted->wpdb_state()['rows_affected']
+		&& '9' === (string) ( $shadow_rows->wpdb_state()['last_result'][0]->id ?? '' )
+		&& true === $shadow_dropped->return_value()
+		&& 'permanent' === (string) ( $permanent_rows_after_shadow->wpdb_state()['last_result'][0]->event_key ?? '' )
+		&& false === $cold_temporary->return_value(),
 );
 
 $failed = false;

From 81a8a551161b93fe3e8d70eec82a9fb5ebe1587c Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 13:21:39 -0400
Subject: [PATCH 36/53] fix(native): share temporary tables across site
 runtimes

---
 .../class-wp-markdown-native-query-runtime.php    | 15 +++++++++++----
 tests/smoke-native-multisite-prefix-routing.php   |  9 +++++++++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-runtime.php b/inc/native/class-wp-markdown-native-query-runtime.php
index 90fc9df..28fc81c 100644
--- a/inc/native/class-wp-markdown-native-query-runtime.php
+++ b/inc/native/class-wp-markdown-native-query-runtime.php
@@ -253,7 +253,8 @@ public static function runtime(
 		?string $global_state_root = null,
 		?string $global_content_root = null,
 		?WP_Markdown_Native_Advisory_Locks $advisory_locks = null,
-		?string $transaction_state_root = null
+		?string $transaction_state_root = null,
+		?WP_Markdown_Native_Temporary_Tables $temporary_tables = null
 	): WP_Markdown_Native_Query_Runtime {
 		$state_root = self::materialize_state_root( $state_root );
 		if ( null !== $content_root ) {
@@ -270,7 +271,7 @@ public static function runtime(
 			array_filter( array( $state_root, $content_root, $global_state_root, $global_content_root ) )
 		);
 		$registry = self::registry( $state_root, $prefix, $base_prefix, $multisite, $content_root, $global_state_root, $global_content_root );
-		$temporary_tables = new WP_Markdown_Native_Temporary_Tables();
+		$temporary_tables = $temporary_tables ?? new WP_Markdown_Native_Temporary_Tables();
 		$parser = new WP_Markdown_Native_Table_Insert_Parser();
 		$resolved_base = $base_prefix ?? $prefix;
 		$resolved_content = $content_root ?? $state_root;
@@ -644,12 +645,14 @@ final class WP_Markdown_Native_Prefix_Query_Runtime implements WP_Markdown_Query
 	/** @var array<string,WP_Markdown_Native_Query_Runtime> */
 	private array $runtimes = array();
 	private WP_Markdown_Native_Advisory_Locks $advisory_locks;
+	private WP_Markdown_Native_Temporary_Tables $temporary_tables;
 
 	public function __construct(
 		private string $state_root,
 		private string $content_root
 	) {
 		$this->advisory_locks = new WP_Markdown_Native_Advisory_Locks( $state_root );
+		$this->temporary_tables = new WP_Markdown_Native_Temporary_Tables();
 	}
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
@@ -661,7 +664,8 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 				$prefix,
 				false,
 				$this->content_root,
-				advisory_locks: $this->advisory_locks
+				advisory_locks: $this->advisory_locks,
+				temporary_tables: $this->temporary_tables
 			);
 		}
 		return $this->runtimes[ $prefix ]->execute( $request );
@@ -718,6 +722,7 @@ final class WP_Markdown_Native_Multisite_Query_Runtime implements WP_Markdown_Qu
 	private string $state_root;
 	private string $content_root;
 	private WP_Markdown_Native_Advisory_Locks $advisory_locks;
+	private WP_Markdown_Native_Temporary_Tables $temporary_tables;
 
 	public function __construct(
 		string $state_root,
@@ -730,6 +735,7 @@ public function __construct(
 		$this->state_root = rtrim( $state_root, '/\\' );
 		$this->content_root = rtrim( $content_root, '/\\' );
 		$this->advisory_locks = new WP_Markdown_Native_Advisory_Locks( $this->state_root );
+		$this->temporary_tables = new WP_Markdown_Native_Temporary_Tables();
 	}
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
@@ -764,7 +770,8 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 					$this->state_root,
 					$this->content_root,
 					$this->advisory_locks,
-					$this->state_root
+					$this->state_root,
+					$this->temporary_tables
 				);
 			} catch ( Throwable ) {
 				return WP_Markdown_Query_Result::failure(
diff --git a/tests/smoke-native-multisite-prefix-routing.php b/tests/smoke-native-multisite-prefix-routing.php
index d23827b..8daf9b1 100644
--- a/tests/smoke-native-multisite-prefix-routing.php
+++ b/tests/smoke-native-multisite-prefix-routing.php
@@ -29,6 +29,11 @@
 $cross_scope_rollback = $runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK', 'wp_' ) );
 $site_after_rollback = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_2_posts WHERE post_name = 'site-transaction'", 'wp_2_' ) );
 $network_after_rollback = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_name = 'network-transaction'", 'wp_' ) );
+$temporary_created = $runtime->execute( new WP_Markdown_Query_Request( 'CREATE TEMPORARY TABLE wp_2_session_probe (id bigint unsigned NOT NULL, PRIMARY KEY (id))', 'wp_2_' ) );
+$temporary_inserted = $runtime->execute( new WP_Markdown_Query_Request( 'INSERT INTO wp_2_session_probe (id) VALUES (7)', 'wp_2_' ) );
+// Construct the base-prefix runtime after site 2, as switch_to_blog() does.
+$base_scope = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT option_value FROM wp_options WHERE option_name = \'siteurl\'', 'wp_' ) );
+$temporary_after_switch = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT id FROM wp_2_session_probe', 'wp_2_' ) );
 
 $listed = array_map( static fn( object $row ): string => (string) array_values( get_object_vars( $row ) )[0], $tables->wpdb_state()['last_result'] );
 $checks = array(
@@ -46,6 +51,10 @@
 		&& 0 === $network_after_rollback->wpdb_state()['num_rows']
 		&& empty( glob( $root . '/sites/2/post/*.md' ) )
 		&& empty( glob( $root . '/post/*.md' ) ),
+	'temporary tables retain one logical wpdb session across lazy site-prefix runtimes' => $temporary_created->succeeded()
+		&& 1 === $temporary_inserted->return_value()
+		&& $base_scope->succeeded()
+		&& '7' === (string) ( $temporary_after_switch->wpdb_state()['last_result'][0]->id ?? '' ),
 );
 
 $failed = 0;

From 393a0aa67caa877922530e01de302e41710ea00d Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 13:28:04 -0400
Subject: [PATCH 37/53] fix(native): project temporary tables across site
 registries

---
 ...class-wp-markdown-native-query-runtime.php |  1 +
 .../class-wp-markdown-native-query-schema.php | 24 +++++++++++++++++++
 ...ss-wp-markdown-native-schema-mutations.php |  5 ++--
 ...ss-wp-markdown-native-temporary-tables.php | 12 +++++++---
 4 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-runtime.php b/inc/native/class-wp-markdown-native-query-runtime.php
index 28fc81c..747eec8 100644
--- a/inc/native/class-wp-markdown-native-query-runtime.php
+++ b/inc/native/class-wp-markdown-native-query-runtime.php
@@ -272,6 +272,7 @@ public static function runtime(
 		);
 		$registry = self::registry( $state_root, $prefix, $base_prefix, $multisite, $content_root, $global_state_root, $global_content_root );
 		$temporary_tables = $temporary_tables ?? new WP_Markdown_Native_Temporary_Tables();
+		$registry->temporary_tables( $temporary_tables );
 		$parser = new WP_Markdown_Native_Table_Insert_Parser();
 		$resolved_base = $base_prefix ?? $prefix;
 		$resolved_content = $content_root ?? $state_root;
diff --git a/inc/native/class-wp-markdown-native-query-schema.php b/inc/native/class-wp-markdown-native-query-schema.php
index 9a0d344..434b1be 100644
--- a/inc/native/class-wp-markdown-native-query-schema.php
+++ b/inc/native/class-wp-markdown-native-query-schema.php
@@ -712,6 +712,11 @@ final class WP_Markdown_Native_Table_Registry {
 	private array $definitions = array();
 	/** @var array<string,array{table:?array{schema:WP_Markdown_Native_Table_Schema,provider:WP_Markdown_Native_Table_Provider},definition:?array<string,mixed>}> */
 	private array $shadows = array();
+	private ?WP_Markdown_Native_Temporary_Tables $temporary_tables = null;
+
+	public function temporary_tables( WP_Markdown_Native_Temporary_Tables $temporary_tables ): void {
+		$this->temporary_tables = $temporary_tables;
+	}
 
 	public function register(
 		string $table,
@@ -730,6 +735,7 @@ public function register(
 
 	/** @return array{schema:WP_Markdown_Native_Table_Schema,provider:WP_Markdown_Native_Table_Provider}|null */
 	public function table( string $table ): ?array {
+		$this->synchronize_temporary_table( $table );
 		return $this->tables[ $table ] ?? null;
 	}
 
@@ -745,6 +751,7 @@ public function register_definition( string $table, array $definition ): void {
 
 	/** @return array<string,mixed>|null */
 	public function definition( string $table ): ?array {
+		$this->synchronize_temporary_table( $table );
 		return $this->definitions[ $table ] ?? null;
 	}
 
@@ -825,4 +832,21 @@ public function forget_snapshots(): void {
 	public function table_names(): array {
 		return array_keys( $this->definitions );
 	}
+
+	/** Project the connection's temporary overlay into this prefix-local registry. */
+	private function synchronize_temporary_table( string $table ): void {
+		if ( null === $this->temporary_tables ) {
+			return;
+		}
+		$temporary = $this->temporary_tables->table( $table );
+		if ( null === $temporary ) {
+			if ( isset( $this->shadows[ $table ] ) ) {
+				$this->unshadow( $table );
+			}
+			return;
+		}
+		if ( ! isset( $this->shadows[ $table ] ) ) {
+			$this->shadow( $table, $temporary['schema'], $temporary['provider'], $temporary['definition'] );
+		}
+	}
 }
diff --git a/inc/native/class-wp-markdown-native-schema-mutations.php b/inc/native/class-wp-markdown-native-schema-mutations.php
index 3dddc1b..a2c74e9 100644
--- a/inc/native/class-wp-markdown-native-schema-mutations.php
+++ b/inc/native/class-wp-markdown-native-schema-mutations.php
@@ -118,12 +118,13 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 				return $this->failure( 'unsupported_schema', 'mdi-native cannot compile the requested table definition.' );
 			}
 			if ( $temporary && null !== $this->temporary_tables ) {
+				$provider = null === $schema ? null : new WP_Markdown_Native_JSON_Snapshot_Provider( $root, $schema, $suffix . '.json' );
 				if ( null === $schema ) {
 					$this->registry->shadow( $table, null, null, $definition );
 				} else {
-					$this->registry->shadow( $table, $schema, new WP_Markdown_Native_JSON_Snapshot_Provider( $root, $schema, $suffix . '.json' ), $definition );
+					$this->registry->shadow( $table, $schema, $provider, $definition );
 				}
-				$this->temporary_tables->add( $table );
+				$this->temporary_tables->add( $table, $schema, $provider, $definition );
 			} elseif ( null === $schema ) {
 				$this->registry->register_definition( $table, $definition );
 			} else {
diff --git a/inc/native/class-wp-markdown-native-temporary-tables.php b/inc/native/class-wp-markdown-native-temporary-tables.php
index d47a11c..d82c135 100644
--- a/inc/native/class-wp-markdown-native-temporary-tables.php
+++ b/inc/native/class-wp-markdown-native-temporary-tables.php
@@ -7,7 +7,7 @@
 
 final class WP_Markdown_Native_Temporary_Tables {
 	private string $root;
-	/** @var array<string,true> */
+	/** @var array<string,array{schema:?WP_Markdown_Native_Table_Schema,provider:?WP_Markdown_Native_Table_Provider,definition:array<string,mixed>}> */
 	private array $tables = array();
 
 	public function __construct() {
@@ -34,8 +34,14 @@ public function has( string $table ): bool {
 		return isset( $this->tables[ $table ] );
 	}
 
-	public function add( string $table ): void {
-		$this->tables[ $table ] = true;
+	/** @param array<string,mixed> $definition */
+	public function add( string $table, ?WP_Markdown_Native_Table_Schema $schema, ?WP_Markdown_Native_Table_Provider $provider, array $definition ): void {
+		$this->tables[ $table ] = array( 'schema' => $schema, 'provider' => $provider, 'definition' => $definition );
+	}
+
+	/** @return array{schema:?WP_Markdown_Native_Table_Schema,provider:?WP_Markdown_Native_Table_Provider,definition:array<string,mixed>}|null */
+	public function table( string $table ): ?array {
+		return $this->tables[ $table ] ?? null;
 	}
 
 	public function remove( string $table ): void {

From 8b29b207db96c4ada6a0f20dbc88a7aa1ab8ef9e Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 13:32:41 -0400
Subject: [PATCH 38/53] Revert "fix(native): project temporary tables across
 site registries"

This reverts commit 393a0aa67caa877922530e01de302e41710ea00d.
---
 ...class-wp-markdown-native-query-runtime.php |  1 -
 .../class-wp-markdown-native-query-schema.php | 24 -------------------
 ...ss-wp-markdown-native-schema-mutations.php |  5 ++--
 ...ss-wp-markdown-native-temporary-tables.php | 12 +++-------
 4 files changed, 5 insertions(+), 37 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-runtime.php b/inc/native/class-wp-markdown-native-query-runtime.php
index 747eec8..28fc81c 100644
--- a/inc/native/class-wp-markdown-native-query-runtime.php
+++ b/inc/native/class-wp-markdown-native-query-runtime.php
@@ -272,7 +272,6 @@ public static function runtime(
 		);
 		$registry = self::registry( $state_root, $prefix, $base_prefix, $multisite, $content_root, $global_state_root, $global_content_root );
 		$temporary_tables = $temporary_tables ?? new WP_Markdown_Native_Temporary_Tables();
-		$registry->temporary_tables( $temporary_tables );
 		$parser = new WP_Markdown_Native_Table_Insert_Parser();
 		$resolved_base = $base_prefix ?? $prefix;
 		$resolved_content = $content_root ?? $state_root;
diff --git a/inc/native/class-wp-markdown-native-query-schema.php b/inc/native/class-wp-markdown-native-query-schema.php
index 434b1be..9a0d344 100644
--- a/inc/native/class-wp-markdown-native-query-schema.php
+++ b/inc/native/class-wp-markdown-native-query-schema.php
@@ -712,11 +712,6 @@ final class WP_Markdown_Native_Table_Registry {
 	private array $definitions = array();
 	/** @var array<string,array{table:?array{schema:WP_Markdown_Native_Table_Schema,provider:WP_Markdown_Native_Table_Provider},definition:?array<string,mixed>}> */
 	private array $shadows = array();
-	private ?WP_Markdown_Native_Temporary_Tables $temporary_tables = null;
-
-	public function temporary_tables( WP_Markdown_Native_Temporary_Tables $temporary_tables ): void {
-		$this->temporary_tables = $temporary_tables;
-	}
 
 	public function register(
 		string $table,
@@ -735,7 +730,6 @@ public function register(
 
 	/** @return array{schema:WP_Markdown_Native_Table_Schema,provider:WP_Markdown_Native_Table_Provider}|null */
 	public function table( string $table ): ?array {
-		$this->synchronize_temporary_table( $table );
 		return $this->tables[ $table ] ?? null;
 	}
 
@@ -751,7 +745,6 @@ public function register_definition( string $table, array $definition ): void {
 
 	/** @return array<string,mixed>|null */
 	public function definition( string $table ): ?array {
-		$this->synchronize_temporary_table( $table );
 		return $this->definitions[ $table ] ?? null;
 	}
 
@@ -832,21 +825,4 @@ public function forget_snapshots(): void {
 	public function table_names(): array {
 		return array_keys( $this->definitions );
 	}
-
-	/** Project the connection's temporary overlay into this prefix-local registry. */
-	private function synchronize_temporary_table( string $table ): void {
-		if ( null === $this->temporary_tables ) {
-			return;
-		}
-		$temporary = $this->temporary_tables->table( $table );
-		if ( null === $temporary ) {
-			if ( isset( $this->shadows[ $table ] ) ) {
-				$this->unshadow( $table );
-			}
-			return;
-		}
-		if ( ! isset( $this->shadows[ $table ] ) ) {
-			$this->shadow( $table, $temporary['schema'], $temporary['provider'], $temporary['definition'] );
-		}
-	}
 }
diff --git a/inc/native/class-wp-markdown-native-schema-mutations.php b/inc/native/class-wp-markdown-native-schema-mutations.php
index a2c74e9..3dddc1b 100644
--- a/inc/native/class-wp-markdown-native-schema-mutations.php
+++ b/inc/native/class-wp-markdown-native-schema-mutations.php
@@ -118,13 +118,12 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 				return $this->failure( 'unsupported_schema', 'mdi-native cannot compile the requested table definition.' );
 			}
 			if ( $temporary && null !== $this->temporary_tables ) {
-				$provider = null === $schema ? null : new WP_Markdown_Native_JSON_Snapshot_Provider( $root, $schema, $suffix . '.json' );
 				if ( null === $schema ) {
 					$this->registry->shadow( $table, null, null, $definition );
 				} else {
-					$this->registry->shadow( $table, $schema, $provider, $definition );
+					$this->registry->shadow( $table, $schema, new WP_Markdown_Native_JSON_Snapshot_Provider( $root, $schema, $suffix . '.json' ), $definition );
 				}
-				$this->temporary_tables->add( $table, $schema, $provider, $definition );
+				$this->temporary_tables->add( $table );
 			} elseif ( null === $schema ) {
 				$this->registry->register_definition( $table, $definition );
 			} else {
diff --git a/inc/native/class-wp-markdown-native-temporary-tables.php b/inc/native/class-wp-markdown-native-temporary-tables.php
index d82c135..d47a11c 100644
--- a/inc/native/class-wp-markdown-native-temporary-tables.php
+++ b/inc/native/class-wp-markdown-native-temporary-tables.php
@@ -7,7 +7,7 @@
 
 final class WP_Markdown_Native_Temporary_Tables {
 	private string $root;
-	/** @var array<string,array{schema:?WP_Markdown_Native_Table_Schema,provider:?WP_Markdown_Native_Table_Provider,definition:array<string,mixed>}> */
+	/** @var array<string,true> */
 	private array $tables = array();
 
 	public function __construct() {
@@ -34,14 +34,8 @@ public function has( string $table ): bool {
 		return isset( $this->tables[ $table ] );
 	}
 
-	/** @param array<string,mixed> $definition */
-	public function add( string $table, ?WP_Markdown_Native_Table_Schema $schema, ?WP_Markdown_Native_Table_Provider $provider, array $definition ): void {
-		$this->tables[ $table ] = array( 'schema' => $schema, 'provider' => $provider, 'definition' => $definition );
-	}
-
-	/** @return array{schema:?WP_Markdown_Native_Table_Schema,provider:?WP_Markdown_Native_Table_Provider,definition:array<string,mixed>}|null */
-	public function table( string $table ): ?array {
-		return $this->tables[ $table ] ?? null;
+	public function add( string $table ): void {
+		$this->tables[ $table ] = true;
 	}
 
 	public function remove( string $table ): void {

From 0d7b860439fbc27295a9e160b9fe25c634f235a7 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 13:32:41 -0400
Subject: [PATCH 39/53] Revert "fix(native): share temporary tables across site
 runtimes"

This reverts commit 81a8a551161b93fe3e8d70eec82a9fb5ebe1587c.
---
 .../class-wp-markdown-native-query-runtime.php    | 15 ++++-----------
 tests/smoke-native-multisite-prefix-routing.php   |  9 ---------
 2 files changed, 4 insertions(+), 20 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-runtime.php b/inc/native/class-wp-markdown-native-query-runtime.php
index 28fc81c..90fc9df 100644
--- a/inc/native/class-wp-markdown-native-query-runtime.php
+++ b/inc/native/class-wp-markdown-native-query-runtime.php
@@ -253,8 +253,7 @@ public static function runtime(
 		?string $global_state_root = null,
 		?string $global_content_root = null,
 		?WP_Markdown_Native_Advisory_Locks $advisory_locks = null,
-		?string $transaction_state_root = null,
-		?WP_Markdown_Native_Temporary_Tables $temporary_tables = null
+		?string $transaction_state_root = null
 	): WP_Markdown_Native_Query_Runtime {
 		$state_root = self::materialize_state_root( $state_root );
 		if ( null !== $content_root ) {
@@ -271,7 +270,7 @@ public static function runtime(
 			array_filter( array( $state_root, $content_root, $global_state_root, $global_content_root ) )
 		);
 		$registry = self::registry( $state_root, $prefix, $base_prefix, $multisite, $content_root, $global_state_root, $global_content_root );
-		$temporary_tables = $temporary_tables ?? new WP_Markdown_Native_Temporary_Tables();
+		$temporary_tables = new WP_Markdown_Native_Temporary_Tables();
 		$parser = new WP_Markdown_Native_Table_Insert_Parser();
 		$resolved_base = $base_prefix ?? $prefix;
 		$resolved_content = $content_root ?? $state_root;
@@ -645,14 +644,12 @@ final class WP_Markdown_Native_Prefix_Query_Runtime implements WP_Markdown_Query
 	/** @var array<string,WP_Markdown_Native_Query_Runtime> */
 	private array $runtimes = array();
 	private WP_Markdown_Native_Advisory_Locks $advisory_locks;
-	private WP_Markdown_Native_Temporary_Tables $temporary_tables;
 
 	public function __construct(
 		private string $state_root,
 		private string $content_root
 	) {
 		$this->advisory_locks = new WP_Markdown_Native_Advisory_Locks( $state_root );
-		$this->temporary_tables = new WP_Markdown_Native_Temporary_Tables();
 	}
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
@@ -664,8 +661,7 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 				$prefix,
 				false,
 				$this->content_root,
-				advisory_locks: $this->advisory_locks,
-				temporary_tables: $this->temporary_tables
+				advisory_locks: $this->advisory_locks
 			);
 		}
 		return $this->runtimes[ $prefix ]->execute( $request );
@@ -722,7 +718,6 @@ final class WP_Markdown_Native_Multisite_Query_Runtime implements WP_Markdown_Qu
 	private string $state_root;
 	private string $content_root;
 	private WP_Markdown_Native_Advisory_Locks $advisory_locks;
-	private WP_Markdown_Native_Temporary_Tables $temporary_tables;
 
 	public function __construct(
 		string $state_root,
@@ -735,7 +730,6 @@ public function __construct(
 		$this->state_root = rtrim( $state_root, '/\\' );
 		$this->content_root = rtrim( $content_root, '/\\' );
 		$this->advisory_locks = new WP_Markdown_Native_Advisory_Locks( $this->state_root );
-		$this->temporary_tables = new WP_Markdown_Native_Temporary_Tables();
 	}
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
@@ -770,8 +764,7 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 					$this->state_root,
 					$this->content_root,
 					$this->advisory_locks,
-					$this->state_root,
-					$this->temporary_tables
+					$this->state_root
 				);
 			} catch ( Throwable ) {
 				return WP_Markdown_Query_Result::failure(
diff --git a/tests/smoke-native-multisite-prefix-routing.php b/tests/smoke-native-multisite-prefix-routing.php
index 8daf9b1..d23827b 100644
--- a/tests/smoke-native-multisite-prefix-routing.php
+++ b/tests/smoke-native-multisite-prefix-routing.php
@@ -29,11 +29,6 @@
 $cross_scope_rollback = $runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK', 'wp_' ) );
 $site_after_rollback = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_2_posts WHERE post_name = 'site-transaction'", 'wp_2_' ) );
 $network_after_rollback = $runtime->execute( new WP_Markdown_Query_Request( "SELECT ID FROM wp_posts WHERE post_name = 'network-transaction'", 'wp_' ) );
-$temporary_created = $runtime->execute( new WP_Markdown_Query_Request( 'CREATE TEMPORARY TABLE wp_2_session_probe (id bigint unsigned NOT NULL, PRIMARY KEY (id))', 'wp_2_' ) );
-$temporary_inserted = $runtime->execute( new WP_Markdown_Query_Request( 'INSERT INTO wp_2_session_probe (id) VALUES (7)', 'wp_2_' ) );
-// Construct the base-prefix runtime after site 2, as switch_to_blog() does.
-$base_scope = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT option_value FROM wp_options WHERE option_name = \'siteurl\'', 'wp_' ) );
-$temporary_after_switch = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT id FROM wp_2_session_probe', 'wp_2_' ) );
 
 $listed = array_map( static fn( object $row ): string => (string) array_values( get_object_vars( $row ) )[0], $tables->wpdb_state()['last_result'] );
 $checks = array(
@@ -51,10 +46,6 @@
 		&& 0 === $network_after_rollback->wpdb_state()['num_rows']
 		&& empty( glob( $root . '/sites/2/post/*.md' ) )
 		&& empty( glob( $root . '/post/*.md' ) ),
-	'temporary tables retain one logical wpdb session across lazy site-prefix runtimes' => $temporary_created->succeeded()
-		&& 1 === $temporary_inserted->return_value()
-		&& $base_scope->succeeded()
-		&& '7' === (string) ( $temporary_after_switch->wpdb_state()['last_result'][0]->id ?? '' ),
 );
 
 $failed = 0;

From c233045ddc931b89998f2a478726494d66a3aef7 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 14:01:15 -0400
Subject: [PATCH 40/53] fix(native): route core temporary table mutations

---
 ...lass-wp-markdown-native-query-executor.php |  4 +--
 .../class-wp-markdown-native-query-schema.php |  5 ++++
 ...ss-wp-markdown-native-schema-mutations.php |  2 +-
 tests/smoke-native-create-table.php           | 28 +++++++++++++++++++
 4 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 65497f7..59b6308 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -163,7 +163,7 @@ private function execute_unlocked_request( WP_Markdown_Query_Request $request ):
 				: $this->schema_mutations->execute( $request );
 		}
 		$dml_table = $this->dml_table( $request );
-		if ( null !== $dml_table && 0 !== strcasecmp( $request->table_prefix() . 'options', $dml_table ) ) {
+		if ( null !== $dml_table && ( 0 !== strcasecmp( $request->table_prefix() . 'options', $dml_table ) || $this->registry->is_shadowed( $dml_table ) ) ) {
 			return $this->execute_table_dml( $request, $dml_table );
 		}
 		if ( 1 !== preg_match( '/^\s*(?:SELECT\b|(?:\(\s*)+SELECT\b)/i', $request->sql() ) ) {
@@ -2541,7 +2541,7 @@ private function dml_table( WP_Markdown_Query_Request $request ): ?string {
 	}
 
 	private function execute_table_dml( WP_Markdown_Query_Request $request, string $table ): WP_Markdown_Query_Result {
-		if ( 0 === strcasecmp( $request->table_prefix() . 'posts', $table ) ) {
+		if ( 0 === strcasecmp( $request->table_prefix() . 'posts', $table ) && ! $this->registry->is_shadowed( $table ) ) {
 			return null === $this->post_mutations
 				? $this->failure( 'unsupported_grammar', 'mdi-native post mutations are unavailable.' )
 				: $this->post_mutations->execute( $request );
diff --git a/inc/native/class-wp-markdown-native-query-schema.php b/inc/native/class-wp-markdown-native-query-schema.php
index 9a0d344..de9d9d5 100644
--- a/inc/native/class-wp-markdown-native-query-schema.php
+++ b/inc/native/class-wp-markdown-native-query-schema.php
@@ -748,6 +748,11 @@ public function definition( string $table ): ?array {
 		return $this->definitions[ $table ] ?? null;
 	}
 
+	/** Whether a connection-local temporary table currently hides this identifier. */
+	public function is_shadowed( string $table ): bool {
+		return isset( $this->shadows[ $table ] );
+	}
+
 	/**
 	 * Replace a registered table after its schema is altered.
 	 *
diff --git a/inc/native/class-wp-markdown-native-schema-mutations.php b/inc/native/class-wp-markdown-native-schema-mutations.php
index 3dddc1b..abe293f 100644
--- a/inc/native/class-wp-markdown-native-schema-mutations.php
+++ b/inc/native/class-wp-markdown-native-schema-mutations.php
@@ -266,7 +266,7 @@ private function execute_drop( WP_Markdown_Query_Request $request, string $sql )
 			return $this->failure( 'unsupported_schema', 'mdi-native requires a simple table identifier.' );
 		}
 		// Core tables are structural, not plugin state, so they are never dropped.
-		if ( isset( WP_Markdown_Native_Schema_Catalog::definitions()[ $suffix ] ) ) {
+		if ( ! $temporary && isset( WP_Markdown_Native_Schema_Catalog::definitions()[ $suffix ] ) ) {
 			return $this->failure( 'unsupported_schema', 'mdi-native cannot drop a core table.' );
 		}
 		if ( $temporary ) {
diff --git a/tests/smoke-native-create-table.php b/tests/smoke-native-create-table.php
index 02bb257..bc2ead8 100644
--- a/tests/smoke-native-create-table.php
+++ b/tests/smoke-native-create-table.php
@@ -89,6 +89,24 @@ function mdi_native_create_remove_tree( string $root ): void {
 $permanent_rows_after_shadow = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT event_key, owner_id, payload FROM wp_plugin_events' ) );
 $cold_temporary = WP_Markdown_Native_Runtime_Factory::runtime( $root )->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_temporary_generation' ) );
 
+$runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_options (option_name, option_value, autoload) VALUES ('temporary_shadow', 'permanent', 'no')" ) );
+$core_runtime = WP_Markdown_Native_Runtime_Factory::runtime( $root );
+$permanent_options_before = $core_runtime->execute( new WP_Markdown_Query_Request( "SELECT option_value FROM wp_options WHERE option_name = 'temporary_shadow'" ) );
+$temporary_options_created = $core_runtime->execute( new WP_Markdown_Query_Request( 'CREATE TEMPORARY TABLE wp_options (option_name varchar(64) NOT NULL, option_value longtext DEFAULT NULL, PRIMARY KEY (option_name))' ) );
+$temporary_options_inserted = $core_runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_options (option_name, option_value) VALUES ('temporary_shadow', 'temporary')" ) );
+$core_runtime->execute( new WP_Markdown_Query_Request( "UPDATE wp_options SET option_value = 'updated' WHERE option_name = 'temporary_shadow'" ) );
+$temporary_options_rows = $core_runtime->execute( new WP_Markdown_Query_Request( "SELECT option_value FROM wp_options WHERE option_name = 'temporary_shadow'" ) );
+$core_runtime->execute( new WP_Markdown_Query_Request( 'DROP TEMPORARY TABLE wp_options' ) );
+$permanent_options_rows = $core_runtime->execute( new WP_Markdown_Query_Request( "SELECT option_value FROM wp_options WHERE option_name = 'temporary_shadow'" ) );
+
+$permanent_posts_before = $core_runtime->execute( new WP_Markdown_Query_Request( 'SELECT ID FROM wp_posts WHERE ID = 900' ) );
+$temporary_posts_created = $core_runtime->execute( new WP_Markdown_Query_Request( 'CREATE TEMPORARY TABLE wp_posts (ID bigint unsigned NOT NULL, post_title varchar(255) NOT NULL, PRIMARY KEY (ID))' ) );
+$temporary_posts_inserted = $core_runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_posts (ID, post_title) VALUES (900, 'temporary')" ) );
+$core_runtime->execute( new WP_Markdown_Query_Request( "UPDATE wp_posts SET post_title = 'updated' WHERE ID = 900" ) );
+$temporary_posts_rows = $core_runtime->execute( new WP_Markdown_Query_Request( 'SELECT post_title FROM wp_posts WHERE ID = 900' ) );
+$core_runtime->execute( new WP_Markdown_Query_Request( 'DROP TEMPORARY TABLE wp_posts' ) );
+$permanent_posts_rows = $core_runtime->execute( new WP_Markdown_Query_Request( 'SELECT ID FROM wp_posts WHERE ID = 900' ) );
+
 $checks = array(
 	'generic CREATE TABLE returns the WordPress DDL success shape' => true === $created->return_value()
 		&& 0 === $created->wpdb_state()['rows_affected'],
@@ -124,6 +142,16 @@ function mdi_native_create_remove_tree( string $root ): void {
 		&& true === $shadow_dropped->return_value()
 		&& 'permanent' === (string) ( $permanent_rows_after_shadow->wpdb_state()['last_result'][0]->event_key ?? '' )
 		&& false === $cold_temporary->return_value(),
+	'temporary options shadows route DML to their JSON provider and restore the unchanged canonical provider' => true === $temporary_options_created->return_value()
+		&& 'permanent' === (string) ( $permanent_options_before->wpdb_state()['last_result'][0]->option_value ?? '' )
+		&& 1 === $temporary_options_inserted->wpdb_state()['rows_affected']
+		&& 'updated' === (string) ( $temporary_options_rows->wpdb_state()['last_result'][0]->option_value ?? '' )
+		&& 'permanent' === (string) ( $permanent_options_rows->wpdb_state()['last_result'][0]->option_value ?? '' ),
+	'temporary posts shadows route DML to their JSON provider and restore the unchanged canonical provider' => true === $temporary_posts_created->return_value()
+		&& array() === $permanent_posts_before->wpdb_state()['last_result']
+		&& 1 === $temporary_posts_inserted->wpdb_state()['rows_affected']
+		&& 'updated' === (string) ( $temporary_posts_rows->wpdb_state()['last_result'][0]->post_title ?? '' )
+		&& array() === $permanent_posts_rows->wpdb_state()['last_result'],
 );
 
 $failed = false;

From 9af43cccfe1943df37c23a8abc00f01a2e3ae423 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 15:06:39 -0400
Subject: [PATCH 41/53] fix(native): parse and validate table index hints

---
 .../class-wp-markdown-native-query-ast.php    | 11 +++--
 ...ass-wp-markdown-native-query-contracts.php |  6 ++-
 ...lass-wp-markdown-native-query-executor.php | 23 +++++++++
 .../class-wp-markdown-native-query-parser.php | 49 +++++++++++++++----
 tests/smoke-native-join-query.php             |  5 ++
 5 files changed, 80 insertions(+), 14 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-ast.php b/inc/native/class-wp-markdown-native-query-ast.php
index 547c998..96cf946 100644
--- a/inc/native/class-wp-markdown-native-query-ast.php
+++ b/inc/native/class-wp-markdown-native-query-ast.php
@@ -277,7 +277,8 @@ public function __construct(
 		private readonly array $union_orders = array(),
 		private readonly ?int $union_limit = null,
 		private readonly int $union_limit_offset = 0,
-		private readonly array $group_expressions = array()
+		private readonly array $group_expressions = array(),
+		private readonly array $index_hints = array()
 	) {}
 
 	public function selects_all(): bool {
@@ -387,15 +388,17 @@ public function union_all(): bool { return $this->union_all; }
 	public function union_orders(): array { return $this->union_orders; }
 	public function union_limit(): ?int { return $this->union_limit; }
 	public function union_limit_offset(): int { return $this->union_limit_offset; }
+	/** @return array<int,array{table:string,mode:string,indexes:array<int,string>}> */
+	public function index_hints(): array { return $this->index_hints; }
 
 	/** Attach a query-expression branch without confusing its local clauses with UNION clauses. */
 	public function with_union( self $union, bool $all ): self {
-		return new self( $this->select_all, $this->count_all, $this->projection, $this->table, $this->predicates, $this->orders, $this->limit, $this->alias, $this->joins, $this->calculates_found_rows, $this->limit_offset, $this->distinct, $this->contradiction, $this->group_by, $this->aggregates, $this->scalar_projection, $this->having, $this->subqueries, $union, $this->scalar_predicates, $this->scalar_having, $this->group_expression, $this->boolean_predicate, $this->derived, $all, $this->union_orders, $this->union_limit, $this->union_limit_offset );
+		return new self( $this->select_all, $this->count_all, $this->projection, $this->table, $this->predicates, $this->orders, $this->limit, $this->alias, $this->joins, $this->calculates_found_rows, $this->limit_offset, $this->distinct, $this->contradiction, $this->group_by, $this->aggregates, $this->scalar_projection, $this->having, $this->subqueries, $union, $this->scalar_predicates, $this->scalar_having, $this->group_expression, $this->boolean_predicate, $this->derived, $all, $this->union_orders, $this->union_limit, $this->union_limit_offset, $this->group_expressions, $this->index_hints );
 	}
 
 	/** @param array<int,array{column:WP_Markdown_Native_SQL_Identifier,descending:bool}> $orders */
 	public function with_union_tail( array $orders, ?int $limit, int $offset ): self {
-		return new self( $this->select_all, $this->count_all, $this->projection, $this->table, $this->predicates, $this->orders, $this->limit, $this->alias, $this->joins, $this->calculates_found_rows, $this->limit_offset, $this->distinct, $this->contradiction, $this->group_by, $this->aggregates, $this->scalar_projection, $this->having, $this->subqueries, $this->union, $this->scalar_predicates, $this->scalar_having, $this->group_expression, $this->boolean_predicate, $this->derived, $this->union_all, $orders, $limit, $offset );
+		return new self( $this->select_all, $this->count_all, $this->projection, $this->table, $this->predicates, $this->orders, $this->limit, $this->alias, $this->joins, $this->calculates_found_rows, $this->limit_offset, $this->distinct, $this->contradiction, $this->group_by, $this->aggregates, $this->scalar_projection, $this->having, $this->subqueries, $this->union, $this->scalar_predicates, $this->scalar_having, $this->group_expression, $this->boolean_predicate, $this->derived, $this->union_all, $orders, $limit, $offset, $this->group_expressions, $this->index_hints );
 	}
 
 	public function append_union( self $branch, bool $all ): self {
@@ -406,6 +409,6 @@ public function append_union( self $branch, bool $all ): self {
 
 	/** Remove clauses that syntactically follow an unparenthesized UNION branch. */
 	public function without_order_limit(): self {
-		return new self( $this->select_all, $this->count_all, $this->projection, $this->table, $this->predicates, array(), null, $this->alias, $this->joins, $this->calculates_found_rows, 0, $this->distinct, $this->contradiction, $this->group_by, $this->aggregates, $this->scalar_projection, $this->having, $this->subqueries, $this->union, $this->scalar_predicates, $this->scalar_having, $this->group_expression, $this->boolean_predicate, $this->derived, $this->union_all, $this->union_orders, $this->union_limit, $this->union_limit_offset );
+		return new self( $this->select_all, $this->count_all, $this->projection, $this->table, $this->predicates, array(), null, $this->alias, $this->joins, $this->calculates_found_rows, 0, $this->distinct, $this->contradiction, $this->group_by, $this->aggregates, $this->scalar_projection, $this->having, $this->subqueries, $this->union, $this->scalar_predicates, $this->scalar_having, $this->group_expression, $this->boolean_predicate, $this->derived, $this->union_all, $this->union_orders, $this->union_limit, $this->union_limit_offset, $this->group_expressions, $this->index_hints );
 	}
 }
diff --git a/inc/native/class-wp-markdown-native-query-contracts.php b/inc/native/class-wp-markdown-native-query-contracts.php
index 31dd2e0..180b683 100644
--- a/inc/native/class-wp-markdown-native-query-contracts.php
+++ b/inc/native/class-wp-markdown-native-query-contracts.php
@@ -286,13 +286,17 @@ public function __construct(
 		private readonly array $union_order_by = array(),
 		private readonly ?int $union_limit = null,
 		private readonly int $union_limit_offset = 0,
-		private readonly array $group_expressions = array()
+		private readonly array $group_expressions = array(),
+		private readonly array $index_hints = array()
 	) {}
 
 	public function table(): string {
 		return $this->table;
 	}
 
+	/** @return array<int,array{table:string,mode:string,indexes:array<int,string>}> */
+	public function index_hints(): array { return $this->index_hints; }
+
 	/** @return array<int,string> */
 	public function projection(): array {
 		return $this->projection;
diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 59b6308..19667ab 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -349,6 +349,10 @@ private function advisory_lock_query( string $sql ): ?WP_Markdown_Query_Result {
 	}
 
 	private function execute_query_plan( WP_Markdown_Native_Query_Plan $plan, bool $allow_union = true ): WP_Markdown_Query_Result {
+		$hint_error = $this->validate_index_hints( $plan );
+		if ( null !== $hint_error ) {
+			return $hint_error;
+		}
 		if ( $allow_union && null !== $plan->union() ) {
 			return $this->execute_union( $plan );
 		}
@@ -2533,6 +2537,25 @@ private function execute_transaction_control( array $control ): WP_Markdown_Quer
 		return WP_Markdown_Query_Result::mutated( 0 );
 	}
 
+	/** Hints affect access strategy, not rows; validate names before using native planning. */
+	private function validate_index_hints( WP_Markdown_Native_Query_Plan $plan ): ?WP_Markdown_Query_Result {
+		foreach ( $plan->index_hints() as $hint ) {
+			$definition = $this->registry->definition( $hint['table'] );
+			if ( null === $definition ) {
+				return $this->failure( 'unsupported_table', 'mdi-native cannot validate an index hint for an unknown table.' );
+			}
+			$names = array_map( static fn( array $index ): string => strtolower( $index['name'] ), $definition['indexes'] ?? array() );
+			foreach ( $hint['indexes'] as $name ) {
+				$name = strtolower( $name );
+				$matches = in_array( $name, $names, true ) ? array( $name ) : array_values( array_filter( $names, static fn( string $index ): bool => str_starts_with( $index, $name ) ) );
+				if ( 1 !== count( $matches ) ) {
+					return $this->failure( 'unsupported_index_hint', 'mdi-native requires an existing, unambiguous index in a table hint.' );
+				}
+			}
+		}
+		return null === $plan->union() ? null : $this->validate_index_hints( $plan->union() );
+	}
+
 	private function dml_table( WP_Markdown_Query_Request $request ): ?string {
 		if ( 1 === preg_match( '/^\s*(?:INSERT(?:\s+IGNORE)?\s+INTO|REPLACE(?:\s+INTO)?|UPDATE|DELETE\s+FROM)\s+`?([A-Za-z_][A-Za-z0-9_]*)`?/i', $request->sql(), $match ) ) {
 			return $match[1];
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index d488cdd..cf9100f 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -300,7 +300,8 @@ public function lower( WP_Markdown_Native_SQL_Select|WP_Markdown_Native_SQL_Foun
 			array_map( fn( array $item ): array => array( 'column' => $item['column']->name(), 'descending' => $item['descending'], 'numeric' => str_starts_with( $item['column']->name(), '__union_ordinal_' ) ), $ast->union_orders() ),
 			$ast->union_limit(),
 			$ast->union_limit_offset(),
-			array_map( fn( WP_Markdown_Native_SQL_Scalar_Expression $expression ): WP_Markdown_Native_Query_Scalar_Expression => $this->lower_scalar_expression( $expression, $base_source, $flat_source ), $ast->group_expressions() )
+			array_map( fn( WP_Markdown_Native_SQL_Scalar_Expression $expression ): WP_Markdown_Native_Query_Scalar_Expression => $this->lower_scalar_expression( $expression, $base_source, $flat_source ), $ast->group_expressions() ),
+			$ast->index_hints()
 		);
 	}
 
@@ -567,11 +568,12 @@ private function select( bool $nested ): WP_Markdown_Native_SQL_Select|WP_Markdo
 		}
 
 		$this->expect_keyword( 'FROM' );
-		list( $table, $alias, $derived ) = $this->source( true );
+		list( $table, $alias, $derived, $index_hints ) = $this->source( true );
 		$joins = array();
 		while ( true ) {
 			if ( $this->match_type( WP_Markdown_Native_SQL_Token::COMMA ) ) {
-				list( $join_table, $join_alias, $join_derived ) = $this->source( false );
+				list( $join_table, $join_alias, $join_derived, $join_hints ) = $this->source( false );
+				$index_hints = array_merge( $index_hints, $join_hints );
 				$joins[] = new WP_Markdown_Native_SQL_Join( $join_table, $join_alias, null, null, false, array(), $join_derived );
 				continue;
 			}
@@ -579,7 +581,8 @@ private function select( bool $nested ): WP_Markdown_Native_SQL_Select|WP_Markdo
 			if ( null === $join_kind ) {
 				break;
 			}
-			list( $join_table, $join_alias, $join_derived ) = $this->source( false );
+			list( $join_table, $join_alias, $join_derived, $join_hints ) = $this->source( false );
+			$index_hints = array_merge( $index_hints, $join_hints );
 			$this->expect_keyword( 'ON' );
 			$on_predicates = $this->disjunction( true );
 			$equality = null;
@@ -825,23 +828,51 @@ private function select( bool $nested ): WP_Markdown_Native_SQL_Select|WP_Markdo
 		if ( ! $nested && $this->match_keyword( 'FOR' ) ) {
 			$this->expect_keyword( 'UPDATE' );
 		}
-		return new WP_Markdown_Native_SQL_Select( $select_all, $count_all, $projection, $table, $predicates, $orders, $limit, $alias, $joins, $calculate_found_rows, $limit_offset, $distinct, $this->contradiction, $group, $aggregates, $scalar_projection, $having, $subqueries, $union, $scalar_predicates, $scalar_having, $grouped ? $group_expression : null, $boolean_predicate, $derived, $union_all, $union_orders, $union_limit, $union_limit_offset, $grouped ? $group_expressions : array() );
+		return new WP_Markdown_Native_SQL_Select( $select_all, $count_all, $projection, $table, $predicates, $orders, $limit, $alias, $joins, $calculate_found_rows, $limit_offset, $distinct, $this->contradiction, $group, $aggregates, $scalar_projection, $having, $subqueries, $union, $scalar_predicates, $scalar_having, $grouped ? $group_expression : null, $boolean_predicate, $derived, $union_all, $union_orders, $union_limit, $union_limit_offset, $grouped ? $group_expressions : array(), $index_hints );
 	}
 
-	/** @return array{WP_Markdown_Native_SQL_Identifier,?WP_Markdown_Native_SQL_Identifier,?WP_Markdown_Native_SQL_Select} */
+	/** @return array{WP_Markdown_Native_SQL_Identifier,?WP_Markdown_Native_SQL_Identifier,?WP_Markdown_Native_SQL_Select,array} */
 	private function source( bool $base ): array {
 		if ( ! $this->match_type( WP_Markdown_Native_SQL_Token::LEFT_PAREN ) ) {
 			$table = $this->unqualified_identifier();
 			$alias = null;
 			if ( $this->match_keyword( 'AS' ) ) {
 				$alias = $this->unqualified_identifier();
-			} elseif ( $this->matches_identifier() && ( ! $base || ! $this->is_on() ) ) {
+			} elseif ( $this->matches_identifier() && ! in_array( strtoupper( (string) $this->current()->value() ), array( 'USE', 'FORCE', 'IGNORE' ), true ) && ( ! $base || ! $this->is_on() ) ) {
 				$alias = $this->unqualified_identifier();
 			}
 			if ( ! $base && null === $alias ) {
 				$alias = $table;
 			}
-			return array( $table, $alias, null );
+			$hints = array();
+			while ( WP_Markdown_Native_SQL_Token::WORD === $this->current()->type() && in_array( strtoupper( (string) $this->current()->value() ), array( 'USE', 'FORCE', 'IGNORE' ), true ) ) {
+				$mode = strtoupper( (string) $this->current()->value() );
+				++$this->current;
+				if ( WP_Markdown_Native_SQL_Token::WORD !== $this->current()->type() || ! in_array( strtoupper( (string) $this->current()->value() ), array( 'INDEX', 'KEY' ), true ) ) {
+					$this->unsupported( $this->current() );
+				}
+				++$this->current;
+				if ( $this->match_keyword( 'FOR' ) ) {
+					if ( ! $this->match_keyword( 'JOIN' ) ) {
+						if ( ! $this->match_keyword( 'ORDER' ) && ! $this->match_keyword( 'GROUP' ) ) {
+							$this->unsupported( $this->current() );
+						}
+						$this->expect_keyword( 'BY' );
+					}
+				}
+				$this->expect_type( WP_Markdown_Native_SQL_Token::LEFT_PAREN );
+				$indexes = array();
+				if ( ! $this->match_type( WP_Markdown_Native_SQL_Token::RIGHT_PAREN ) ) {
+					do {
+						$indexes[] = $this->unqualified_identifier()->name();
+					} while ( $this->match_type( WP_Markdown_Native_SQL_Token::COMMA ) );
+					$this->expect_type( WP_Markdown_Native_SQL_Token::RIGHT_PAREN );
+				} elseif ( 'USE' !== $mode ) {
+					$this->unsupported( $this->current() );
+				}
+				$hints[] = array( 'table' => $table->name(), 'mode' => $mode, 'indexes' => $indexes );
+			}
+			return array( $table, $alias, null, $hints );
 		}
 		$derived = $this->select( true );
 		if ( ! $derived instanceof WP_Markdown_Native_SQL_Select ) {
@@ -850,7 +881,7 @@ private function source( bool $base ): array {
 		$this->expect_type( WP_Markdown_Native_SQL_Token::RIGHT_PAREN );
 		$this->match_keyword( 'AS' );
 		$alias = $this->unqualified_identifier();
-		return array( $alias, $alias, $derived );
+		return array( $alias, $alias, $derived, array() );
 	}
 
 	private function matches_scalar_expression(): bool {
diff --git a/tests/smoke-native-join-query.php b/tests/smoke-native-join-query.php
index 77841d3..ced8295 100644
--- a/tests/smoke-native-join-query.php
+++ b/tests/smoke-native-join-query.php
@@ -74,6 +74,9 @@ public function read( WP_Markdown_Native_Table_Access $access ): iterable|WP_Mar
 $plan = ( new WP_Markdown_Native_Query_Parser() )->parse( $query );
 $result = $runtime->execute( new WP_Markdown_Query_Request( $query ) );
 $state = $result->wpdb_state();
+$hinted = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tr JOIN', 'tr FORCE INDEX (term_taxonomy_id) JOIN', $query ) ) );
+$bad_hint = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tr JOIN', 'tr FORCE INDEX (missing_index) JOIN', $query ) ) );
+$joined_hint = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tt ON', 'tt USE KEY FOR JOIN (PRIMARY) ON', $query ) ) );
 $missing = $runtime->execute( new WP_Markdown_Query_Request( str_replace( '=41', '=404', $query ) ) );
 $unbounded = $runtime->execute( new WP_Markdown_Query_Request( substr( $query, 0, strpos( $query, ' WHERE' ) ) ) );
 $unindexed_filter = $runtime->execute( new WP_Markdown_Query_Request( substr( $query, 0, strpos( $query, ' WHERE' ) ) . " WHERE tt.description = ''" ) );
@@ -213,6 +216,8 @@ public function read( WP_Markdown_Native_Table_Access $access ): iterable|WP_Mar
 $meta_result = ( new WP_Markdown_Native_Query_Runtime( $meta_registry ) )->execute( new WP_Markdown_Query_Request( $meta_query ) );
 
 $checks = array(
+	'validated source index hints preserve taxonomy JOIN results' => $hinted->succeeded() && $result->corpus_result() === $hinted->corpus_result() && $joined_hint->succeeded() && $result->corpus_result() === $joined_hint->corpus_result(),
+	'unknown hinted indexes fail instead of silently executing' => ! $bad_hint->succeeded() && 'unsupported_index_hint' === ( $bad_hint->diagnostic()['reason'] ?? null ),
 	'tokenizer and parser lower aliases and chained equality JOINs into typed contracts' => $plan instanceof WP_Markdown_Native_Query_Plan
 		&& 'tr' === $plan->table_alias()
 		&& array( 'tr', 'tt', 't' ) === $plan->projection_sources()

From 932c91659ca5738369db3b6af43a3a5813489a5f Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 15:32:57 -0400
Subject: [PATCH 42/53] test(native): protect composed index hint semantics

---
 inc/native/class-wp-markdown-native-query-parser.php | 9 ++++++++-
 tests/smoke-native-join-query.php                    | 5 +++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index cf9100f..af47f51 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -838,15 +838,22 @@ private function source( bool $base ): array {
 			$alias = null;
 			if ( $this->match_keyword( 'AS' ) ) {
 				$alias = $this->unqualified_identifier();
-			} elseif ( $this->matches_identifier() && ! in_array( strtoupper( (string) $this->current()->value() ), array( 'USE', 'FORCE', 'IGNORE' ), true ) && ( ! $base || ! $this->is_on() ) ) {
+			} elseif ( $this->matches_identifier() && ( WP_Markdown_Native_SQL_Token::QUOTED_IDENTIFIER === $this->current()->type() || ! in_array( strtoupper( (string) $this->current()->value() ), array( 'USE', 'FORCE', 'IGNORE' ), true ) ) && ( ! $base || ! $this->is_on() ) ) {
 				$alias = $this->unqualified_identifier();
 			}
 			if ( ! $base && null === $alias ) {
 				$alias = $table;
 			}
 			$hints = array();
+			$access_mode = null;
 			while ( WP_Markdown_Native_SQL_Token::WORD === $this->current()->type() && in_array( strtoupper( (string) $this->current()->value() ), array( 'USE', 'FORCE', 'IGNORE' ), true ) ) {
 				$mode = strtoupper( (string) $this->current()->value() );
+				if ( 'IGNORE' !== $mode ) {
+					if ( null !== $access_mode && $access_mode !== $mode ) {
+						$this->unsupported( $this->current() );
+					}
+					$access_mode = $mode;
+				}
 				++$this->current;
 				if ( WP_Markdown_Native_SQL_Token::WORD !== $this->current()->type() || ! in_array( strtoupper( (string) $this->current()->value() ), array( 'INDEX', 'KEY' ), true ) ) {
 					$this->unsupported( $this->current() );
diff --git a/tests/smoke-native-join-query.php b/tests/smoke-native-join-query.php
index ced8295..3aa46be 100644
--- a/tests/smoke-native-join-query.php
+++ b/tests/smoke-native-join-query.php
@@ -77,6 +77,9 @@ public function read( WP_Markdown_Native_Table_Access $access ): iterable|WP_Mar
 $hinted = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tr JOIN', 'tr FORCE INDEX (term_taxonomy_id) JOIN', $query ) ) );
 $bad_hint = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tr JOIN', 'tr FORCE INDEX (missing_index) JOIN', $query ) ) );
 $joined_hint = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tt ON', 'tt USE KEY FOR JOIN (PRIMARY) ON', $query ) ) );
+$empty_use_hint = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tr JOIN', 'tr USE INDEX () JOIN', $query ) ) );
+$mixed_hints = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tr JOIN', 'tr USE INDEX (PRIMARY) FORCE INDEX (term_taxonomy_id) JOIN', $query ) ) );
+$union_hint = $runtime->execute( new WP_Markdown_Query_Request( "SELECT object_id FROM wp_term_relationships WHERE object_id=41 UNION SELECT object_id FROM wp_term_relationships FORCE INDEX (missing_index) WHERE object_id=99" ) );
 $missing = $runtime->execute( new WP_Markdown_Query_Request( str_replace( '=41', '=404', $query ) ) );
 $unbounded = $runtime->execute( new WP_Markdown_Query_Request( substr( $query, 0, strpos( $query, ' WHERE' ) ) ) );
 $unindexed_filter = $runtime->execute( new WP_Markdown_Query_Request( substr( $query, 0, strpos( $query, ' WHERE' ) ) . " WHERE tt.description = ''" ) );
@@ -218,6 +221,8 @@ public function read( WP_Markdown_Native_Table_Access $access ): iterable|WP_Mar
 $checks = array(
 	'validated source index hints preserve taxonomy JOIN results' => $hinted->succeeded() && $result->corpus_result() === $hinted->corpus_result() && $joined_hint->succeeded() && $result->corpus_result() === $joined_hint->corpus_result(),
 	'unknown hinted indexes fail instead of silently executing' => ! $bad_hint->succeeded() && 'unsupported_index_hint' === ( $bad_hint->diagnostic()['reason'] ?? null ),
+	'empty USE hints preserve rows while conflicting USE and FORCE hints fail' => $empty_use_hint->succeeded() && $result->corpus_result() === $empty_use_hint->corpus_result() && ! $mixed_hints->succeeded(),
+	'UNION branches retain index-hint validation' => ! $union_hint->succeeded() && 'unsupported_index_hint' === ( $union_hint->diagnostic()['reason'] ?? null ),
 	'tokenizer and parser lower aliases and chained equality JOINs into typed contracts' => $plan instanceof WP_Markdown_Native_Query_Plan
 		&& 'tr' === $plan->table_alias()
 		&& array( 'tr', 'tt', 't' ) === $plan->projection_sources()

From ad5b3a269d964522e73f3b9a5bd1ffb18f4f9658 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 15:39:56 -0400
Subject: [PATCH 43/53] fix(native): preserve mixed LIKE alternatives

---
 .../class-wp-markdown-native-query-parser.php |  8 ++++
 tests/smoke-native-mixed-like-or.php          | 37 +++++++++++++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 tests/smoke-native-mixed-like-or.php

diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index af47f51..4fb3538 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -1173,19 +1173,27 @@ private function coalesce_boolean_groups( array $groups, int $sql_offset ): arra
 	private function requires_boolean_plan( array $groups ): bool {
 		$has_composite_group = false;
 		$has_non_coalescible = false;
+		$has_like = false;
+		$only_single_likes = true;
 		foreach ( $groups as $group ) {
 			$has_composite_group = $has_composite_group || 1 < count( $group );
+			$only_single_likes = $only_single_likes && 1 === count( $group );
 			foreach ( $group as $predicate ) {
 				if ( $predicate instanceof WP_Markdown_Native_SQL_Scalar_Predicate
 					|| $predicate instanceof WP_Markdown_Native_SQL_Subquery_Predicate
 				) {
 					return true;
 				}
+				$has_like = $has_like || 'LIKE' === $predicate->operator();
+				$only_single_likes = $only_single_likes && 'LIKE' === $predicate->operator();
 				$has_non_coalescible = $has_non_coalescible
 					|| null !== $predicate->cast()
 					|| ! in_array( $predicate->operator(), array( '=', 'IN', 'IS NULL', 'LOWER =', 'LIKE' ), true );
 			}
 		}
+		if ( 1 < count( $groups ) && $has_like && ! $only_single_likes ) {
+			return true;
+		}
 		if ( 1 < count( $groups ) && $has_composite_group && $has_non_coalescible ) {
 			return true;
 		}
diff --git a/tests/smoke-native-mixed-like-or.php b/tests/smoke-native-mixed-like-or.php
new file mode 100644
index 0000000..1e930a4
--- /dev/null
+++ b/tests/smoke-native-mixed-like-or.php
@@ -0,0 +1,37 @@
+<?php
+/** Mixed equality and pattern alternatives retain their complete SQL predicate. */
+
+declare( strict_types=1 );
+
+define( 'ABSPATH', __DIR__ . '/' );
+require_once __DIR__ . '/../inc/native/class-wp-markdown-native-query-runtime.php';
+
+$root = sys_get_temp_dir() . '/mdi-mixed-like-' . bin2hex( random_bytes( 6 ) );
+mkdir( $root, 0755 );
+$runtime = WP_Markdown_Native_Runtime_Factory::runtime( $root );
+$checks = array();
+try {
+	$created = $runtime->execute( new WP_Markdown_Query_Request( 'CREATE TABLE wp_event_dates (post_id bigint unsigned NOT NULL, start_datetime datetime NOT NULL, end_datetime datetime NULL, PRIMARY KEY (post_id))' ) );
+	$inserted = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_event_dates (post_id, start_datetime, end_datetime) VALUES (1, '0000-00-00 00:00:00', NULL), (2, '2026-07-15 19:30:00', NULL), (3, '2026-07-16 19:30:00', NULL)" ) );
+	$checks['fixture persists zero and ordinary dates'] = $created->succeeded() && 3 === $inserted->return_value();
+	$queries = array(
+		"start_datetime = '0000-00-00 00:00:00' OR start_datetime LIKE '0000-%'" => array( '1' ),
+		"start_datetime LIKE '0000-%' OR start_datetime = '2026-07-15 19:30:00'" => array( '1', '2' ),
+		"(start_datetime LIKE '0000-%' OR start_datetime = '2026-07-15 19:30:00') AND post_id = 2" => array( '2' ),
+		"start_datetime = '2026-07-15 19:30:00' OR end_datetime LIKE '0000-%'" => array( '2' ),
+	);
+	foreach ( $queries as $predicate => $ids ) {
+		$result = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT post_id FROM wp_event_dates WHERE ' . $predicate . ' ORDER BY post_id' ) );
+		$actual = array_map( static fn( object $row ): string => (string) $row->post_id, $result->wpdb_state()['last_result'] );
+		$checks[ $predicate ] = $result->succeeded() && $ids === $actual;
+	}
+} finally {
+	foreach ( new RecursiveIteratorIterator( new RecursiveDirectoryIterator( $root, FilesystemIterator::SKIP_DOTS ), RecursiveIteratorIterator::CHILD_FIRST ) as $entry ) {
+		$entry->isDir() ? rmdir( $entry->getPathname() ) : unlink( $entry->getPathname() );
+	}
+	rmdir( $root );
+}
+foreach ( $checks as $label => $passed ) {
+	fwrite( $passed ? STDOUT : STDERR, ( $passed ? 'PASS: ' : 'FAIL: ' ) . $label . "\n" );
+}
+exit( in_array( false, $checks, true ) ? 1 : 0 );

From c56c7e6420c71f4d827e76202b14c3dfb27082e6 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 15:54:24 -0400
Subject: [PATCH 44/53] fix(native): preserve aliased column projections

---
 ...lass-wp-markdown-native-query-executor.php | 19 +++++++++++++++----
 .../class-wp-markdown-native-query-parser.php | 11 ++++++++++-
 tests/smoke-native-join-query.php             |  6 ++++++
 3 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 19667ab..5ede95f 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -761,7 +761,7 @@ private function grouped_aggregate_result( array $groups, string $column, array
 		if ( array() === $scalar_projection ) {
 			$columns[] = array( 'name' => $group_name, 'table' => $table, 'type' => $schema->column( $column )->type() );
 		} else {
-			foreach ( $scalar_projection as $scalar ) { $columns[ $scalar['position'] ] = array( 'name' => $scalar['alias'], 'table' => '', 'type' => 253 ); }
+			foreach ( $scalar_projection as $scalar ) { $columns[ $scalar['position'] ] = $this->scalar_projection_column( $scalar, $table, $schema ); }
 			ksort( $columns );
 			$columns = array_values( $columns );
 		}
@@ -1672,9 +1672,10 @@ function ( array $left, array $right ) use ( $plan, $sources ): int {
 			$columns[] = array( 'name' => $column, 'table' => $sources[ $source ]['table'], 'type' => $sources[ $source ]['schema']->column( $column )->type() );
 		}
 		foreach ( $plan->scalar_projection() as $scalar ) {
-			$columns[ $scalar['position'] ] = array( 'name' => $scalar['alias'], 'table' => '', 'type' => 253 );
+			$source = $scalar['expression']->source() ?? $plan->table_alias() ?? $plan->table();
+			$metadata = $this->scalar_projection_column( $scalar, $sources[ $source ]['table'], $sources[ $source ]['schema'] );
+			array_splice( $columns, $scalar['position'], 0, array( $metadata ) );
 		}
-		ksort( $columns );
 		foreach ( $aggregates as $aggregate ) {
 			$columns[] = array( 'name' => $aggregate['alias'], 'table' => '', 'type' => 8 );
 		}
@@ -2119,7 +2120,7 @@ private function result(
 			$projection
 		);
 		$scalar_columns = array();
-		foreach ( $scalar_projection as $scalar ) { $scalar_columns[ $scalar['position'] ] = array( 'name' => $scalar['alias'], 'table' => '', 'type' => 253 ); }
+		foreach ( $scalar_projection as $scalar ) { $scalar_columns[ $scalar['position'] ] = $this->scalar_projection_column( $scalar, $table, $schema ); }
 		$columns = array();
 		$total_columns = count( $regular ) + count( $scalar_columns );
 		for ( $position = 0; $position < $total_columns; ++$position ) {
@@ -2128,6 +2129,16 @@ private function result(
 		return WP_Markdown_Query_Result::selected( $rows, $columns );
 	}
 
+	/** A bare column alias keeps the source column's type and table metadata. */
+	private function scalar_projection_column( array $scalar, string $table, WP_Markdown_Native_Table_Schema $schema ): array {
+		$expression = $scalar['expression'];
+		return array(
+			'name' => $scalar['alias'],
+			'table' => 'column' === $expression->kind() ? $table : '',
+			'type' => 'column' === $expression->kind() ? $schema->column( $expression->column() )->type() : 253,
+		);
+	}
+
 	/** @param array<string,mixed> $source @param array<int,string> $projection @return array<string,string|null> */
 	private function string_row( array $source, array $projection, array $scalar_projection, WP_Markdown_Native_Table_Schema $schema ): array {
 		$regular = array();
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index 4fb3538..7d8acf6 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -563,7 +563,16 @@ private function select( bool $nested ): WP_Markdown_Native_SQL_Select|WP_Markdo
 					);
 					continue;
 				}
-				$projection[] = $this->identifier();
+				$column = $this->identifier();
+				if ( $this->match_keyword( 'AS' ) ) {
+					$scalar_projection[] = array(
+						'expression' => new WP_Markdown_Native_SQL_Scalar_Expression( 'column', $column ),
+						'alias' => $this->unqualified_identifier()->name(),
+						'position' => count( $projection ) + count( $scalar_projection ),
+					);
+				} else {
+					$projection[] = $column;
+				}
 			} while ( $this->match_type( WP_Markdown_Native_SQL_Token::COMMA ) );
 		}
 
diff --git a/tests/smoke-native-join-query.php b/tests/smoke-native-join-query.php
index 3aa46be..128d6a3 100644
--- a/tests/smoke-native-join-query.php
+++ b/tests/smoke-native-join-query.php
@@ -74,6 +74,11 @@ public function read( WP_Markdown_Native_Table_Access $access ): iterable|WP_Mar
 $plan = ( new WP_Markdown_Native_Query_Parser() )->parse( $query );
 $result = $runtime->execute( new WP_Markdown_Query_Request( $query ) );
 $state = $result->wpdb_state();
+$aliased = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tr.object_id, tt.taxonomy, t.slug', 'tr.object_id AS object_identity, tt.taxonomy, t.slug AS term_slug', $query ) ) );
+$expected_aliases = $result->corpus_result();
+$expected_aliases['rows'] = array_map( static fn( array $row ): array => array( 'object_identity' => $row['object_id'], 'taxonomy' => $row['taxonomy'], 'term_slug' => $row['slug'] ), $expected_aliases['rows'] );
+$expected_aliases['columns'][0]['name'] = 'object_identity';
+$expected_aliases['columns'][2]['name'] = 'term_slug';
 $hinted = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tr JOIN', 'tr FORCE INDEX (term_taxonomy_id) JOIN', $query ) ) );
 $bad_hint = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tr JOIN', 'tr FORCE INDEX (missing_index) JOIN', $query ) ) );
 $joined_hint = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tt ON', 'tt USE KEY FOR JOIN (PRIMARY) ON', $query ) ) );
@@ -219,6 +224,7 @@ public function read( WP_Markdown_Native_Table_Access $access ): iterable|WP_Mar
 $meta_result = ( new WP_Markdown_Native_Query_Runtime( $meta_registry ) )->execute( new WP_Markdown_Query_Request( $meta_query ) );
 
 $checks = array(
+	'plain column aliases preserve joined row order and source metadata' => $aliased->succeeded() && $expected_aliases === $aliased->corpus_result(),
 	'validated source index hints preserve taxonomy JOIN results' => $hinted->succeeded() && $result->corpus_result() === $hinted->corpus_result() && $joined_hint->succeeded() && $result->corpus_result() === $joined_hint->corpus_result(),
 	'unknown hinted indexes fail instead of silently executing' => ! $bad_hint->succeeded() && 'unsupported_index_hint' === ( $bad_hint->diagnostic()['reason'] ?? null ),
 	'empty USE hints preserve rows while conflicting USE and FORCE hints fail' => $empty_use_hint->succeeded() && $result->corpus_result() === $empty_use_hint->corpus_result() && ! $mixed_hints->succeeded(),

From 5e9cfade470e1ae9a344fb9287b9432a7f971244 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 16:17:30 -0400
Subject: [PATCH 45/53] fix(native): retain all explicit grouping columns

---
 ...lass-wp-markdown-native-query-executor.php | 22 +++++++------------
 .../class-wp-markdown-native-query-parser.php |  6 ++++-
 tests/smoke-native-aggregates.php             | 22 +++++++++++++++++++
 3 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 5ede95f..ecd8029 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -649,7 +649,7 @@ private function execute_query_plan( WP_Markdown_Native_Query_Plan $plan, bool $
 		}
 		if ( array() !== $aggregates ) {
 			if ( null !== $plan->group_by() ) {
-				return $this->grouped_aggregate_result( $groups, $plan->group_by(), $aggregates, $plan->having(), $plan->scalar_having(), $plan->table(), $schema, $plan->scalar_projection(), $plan->order_by(), $plan->limit_offset(), $plan->limit(), $plan->calculates_found_rows() );
+				return $this->grouped_aggregate_result( $groups, $projection, $aggregates, $plan->having(), $plan->scalar_having(), $plan->table(), $schema, $plan->scalar_projection(), $plan->order_by(), $plan->limit_offset(), $plan->limit(), $plan->calculates_found_rows() );
 			}
 			return $this->aggregate_result( $aggregate_state, $aggregates );
 		}
@@ -730,13 +730,10 @@ private function aggregate_value( array $totals, string $function ): ?string {
 		};
 	}
 
-	private function grouped_aggregate_result( array $groups, string $column, array $aggregates, array $having, array $scalar_having, string $table, WP_Markdown_Native_Table_Schema $schema, array $scalar_projection, array $orders, int $offset, int $limit, bool $calculates_found_rows ): WP_Markdown_Query_Result {
+	private function grouped_aggregate_result( array $groups, array $projection, array $aggregates, array $having, array $scalar_having, string $table, WP_Markdown_Native_Table_Schema $schema, array $scalar_projection, array $orders, int $offset, int $limit, bool $calculates_found_rows ): WP_Markdown_Query_Result {
 		$rows = array();
 		foreach ( $groups as $group ) {
-			$row = array( $column => null === $group['value'] ? null : (string) $group['value'] );
-			foreach ( $scalar_projection as $scalar ) {
-				$row[ $scalar['alias'] ] = $this->string_scalar( $this->evaluate_scalar( $scalar['expression'], $group['row'] ?? array(), $schema ) );
-			}
+			$row = $this->string_row( $group['row'], $projection, $scalar_projection, $schema );
 			foreach ( $aggregates as $index => $aggregate ) {
 				$row[ $aggregate['alias'] ] = $this->aggregate_value( $group['state'][ $index ] ?? array(), $aggregate['function'] );
 			}
@@ -744,8 +741,6 @@ private function grouped_aggregate_result( array $groups, string $column, array
 				$rows[] = $row;
 			}
 		}
-		$group_name = $scalar_projection[0]['alias'] ?? $column;
-		if ( $group_name !== $column ) { foreach ( $rows as &$row ) { $row[ $group_name ] = $row[ $column ]; unset( $row[ $column ] ); } unset( $row ); }
 		if ( array() !== $orders ) {
 			usort( $rows, function ( array $left, array $right ) use ( $orders ): int {
 				foreach ( $orders as $order ) {
@@ -758,12 +753,11 @@ private function grouped_aggregate_result( array $groups, string $column, array
 		if ( $calculates_found_rows ) { $this->last_found_rows = count( $rows ); }
 		$rows = array_values( array_slice( $rows, $offset, PHP_INT_MAX === $limit ? null : $limit ) );
 		$columns = array();
-		if ( array() === $scalar_projection ) {
-			$columns[] = array( 'name' => $group_name, 'table' => $table, 'type' => $schema->column( $column )->type() );
-		} else {
-			foreach ( $scalar_projection as $scalar ) { $columns[ $scalar['position'] ] = $this->scalar_projection_column( $scalar, $table, $schema ); }
-			ksort( $columns );
-			$columns = array_values( $columns );
+		foreach ( $projection as $column ) {
+			$columns[] = array( 'name' => $column, 'table' => $table, 'type' => $schema->column( $column )->type() );
+		}
+		foreach ( $scalar_projection as $scalar ) {
+			array_splice( $columns, $scalar['position'], 0, array( $this->scalar_projection_column( $scalar, $table, $schema ) ) );
 		}
 		foreach ( $aggregates as $aggregate ) { $columns[] = array( 'name' => $aggregate['alias'], 'table' => '', 'type' => 'GROUP_CONCAT' === $aggregate['function'] ? 253 : 8 ); }
 		return WP_Markdown_Query_Result::selected( $rows, $columns );
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index 7d8acf6..666ce5b 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -671,7 +671,11 @@ private function select( bool $nested ): WP_Markdown_Native_SQL_Select|WP_Markdo
 				// grouping column. A wildcard over the grouped table qualifies
 				// because its identity is the group.
 				foreach ( $projection as $column ) {
-					$same_column = $column->name() === $group->name() && $column->qualifier() === $group->qualifier();
+					$same_column = false;
+					foreach ( $group_expressions as $expression ) {
+						$identifier = 'column' === $expression->kind() ? $expression->identifier() : null;
+						$same_column = $same_column || ( null !== $identifier && $column->name() === $identifier->name() && $column->qualifier() === $identifier->qualifier() );
+					}
 					$grouped_wildcard = '*' === $column->name() && null !== $group->qualifier() && $column->qualifier() === $group->qualifier();
 					if ( ! $same_column && ! $grouped_wildcard ) {
 						throw new WP_Markdown_Native_SQL_Parse_Error(
diff --git a/tests/smoke-native-aggregates.php b/tests/smoke-native-aggregates.php
index ef8afed..edb4406 100644
--- a/tests/smoke-native-aggregates.php
+++ b/tests/smoke-native-aggregates.php
@@ -42,8 +42,30 @@ function mdi_aggregate_row( WP_Markdown_Native_Query_Runtime $runtime, string $s
 $textual = mdi_aggregate_row( $runtime, 'SELECT SUM(kind) AS total FROM wp_items' );
 $default_names = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT MAX(score), COUNT(score) FROM wp_items', 'wp_' ) );
 $default_empty = $runtime->execute( new WP_Markdown_Query_Request( "SELECT MAX(score), COUNT(score) FROM wp_items WHERE kind = 'missing'", 'wp_' ) );
+$grouped = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT kind, score, COUNT(id) AS n FROM wp_items GROUP BY kind, score' ) );
+$grouped_alias = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT kind, score AS points, COUNT(id) AS n FROM wp_items GROUP BY kind, score' ) );
+$grouped_join = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT a.kind, b.score, COUNT(a.id) AS n FROM wp_items a JOIN wp_items b ON a.id = b.id GROUP BY a.kind, b.score' ) );
+$grouped_rows = $grouped->corpus_result()['rows'];
+$alias_rows = $grouped_alias->corpus_result()['rows'];
+$joined_rows = $grouped_join->corpus_result()['rows'];
+usort( $grouped_rows, static fn( array $left, array $right ): int => (int) $left['score'] <=> (int) $right['score'] );
+usort( $alias_rows, static fn( array $left, array $right ): int => (int) $left['points'] <=> (int) $right['points'] );
+usort( $joined_rows, static fn( array $left, array $right ): int => (int) $left['score'] <=> (int) $right['score'] );
 
 $checks = array(
+	'multiple explicit grouping columns preserve every projected value' => $grouped->succeeded() && array(
+		array( 'kind' => 'c', 'score' => null, 'n' => '1' ),
+		array( 'kind' => 'a', 'score' => '10', 'n' => '1' ),
+		array( 'kind' => 'b', 'score' => '20', 'n' => '1' ),
+		array( 'kind' => 'a', 'score' => '30', 'n' => '1' ),
+	) === $grouped_rows,
+	'aliased grouping columns retain their position and numeric type' => $grouped_alias->succeeded() && array( 'kind' => 'a', 'points' => '10', 'n' => '1' ) === $alias_rows[1] && '8' === $grouped_alias->corpus_result()['columns'][1]['type'],
+	'joined grouping keys include all explicit columns' => $grouped_join->succeeded() && array(
+		array( 'kind' => 'c', 'score' => null, 'n' => '1' ),
+		array( 'kind' => 'a', 'score' => '10', 'n' => '1' ),
+		array( 'kind' => 'b', 'score' => '20', 'n' => '1' ),
+		array( 'kind' => 'a', 'score' => '30', 'n' => '1' ),
+	) === $joined_rows,
 	'one row reports every ungrouped aggregate' => array( 'total' => '60', 'mean' => '20', 'lowest' => '10', 'highest' => '30' ) === $totals,
 	'COUNT over a column skips its NULL rows' => array( 'scored' => '3' ) === $counts,
 	'COUNT over rows keeps them' => '4' === ( $all_rows['COUNT(*)'] ?? null ),

From 08f02037a4435ab7a61e1319e34baeaee5e992b4 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 16:44:12 -0400
Subject: [PATCH 46/53] fix(native): honor SQL mode for omitted column defaults

---
 README.md                                     | 16 +++++
 ...lass-wp-markdown-native-query-executor.php | 10 +++-
 ...class-wp-markdown-native-query-runtime.php | 30 +++++++---
 ...p-markdown-native-schema-introspection.php |  5 +-
 .../class-wp-markdown-native-sql-session.php  | 60 +++++++++++++++++++
 ...ass-wp-markdown-native-table-mutations.php | 22 ++++++-
 tests/smoke-native-sql-mode-defaults.php      | 43 +++++++++++++
 tests/smoke-native-table-insert.php           |  4 +-
 8 files changed, 175 insertions(+), 15 deletions(-)
 create mode 100644 inc/native/class-wp-markdown-native-sql-session.php
 create mode 100644 tests/smoke-native-sql-mode-defaults.php

diff --git a/README.md b/README.md
index 42d3dcd..645df38 100644
--- a/README.md
+++ b/README.md
@@ -824,3 +824,19 @@ Tested on WordPress 6.9 with SQLite-backed local and Playground-style runtimes:
 ## License
 
 GPL v2 or later.
+## Native SQL Mode Defaults
+
+The native WordPress connection starts with an empty SQL mode, matching its
+existing non-strict `SHOW VARIABLES` contract. Generic table inserts use MySQL
+implicit defaults for supported numeric, string and temporal columns when an
+explicit default is absent. Nullable columns remain NULL; explicit defaults
+take precedence. Missing implicit defaults produce bounded `SHOW WARNINGS`
+records and an exact `@@warning_count`.
+
+`SET [SESSION] sql_mode` and `SELECT @@[SESSION.]sql_mode` support the empty
+mode, `STRICT_TRANS_TABLES`, `STRICT_ALL_TABLES` and `NO_ENGINE_SUBSTITUTION`.
+Strict mode rejects an omitted required column with error 1364. Modes whose
+additional semantics are not implemented are rejected without changing the
+session. This is not a claim of complete MySQL coercion or SQL-mode coverage.
+The mode is connection-local, survives blog switches and resets on logical
+close; it is not persisted in canonical storage.
diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index ecd8029..b21d314 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -56,10 +56,11 @@ public function __construct(
 		private ?WP_Markdown_Native_Post_Mutation_Runtime $post_mutations = null,
 		private int $correlated_subquery_limit = self::MAX_CORRELATED_SUBQUERY_EVALUATIONS,
 		private ?WP_Markdown_Native_Advisory_Locks $advisory_locks = null,
-		?string $database_name = null
+		?string $database_name = null,
+		private WP_Markdown_Native_SQL_Session $session = new WP_Markdown_Native_SQL_Session()
 	) {
 		$this->database_name = $database_name;
-		$this->schema_introspection = new WP_Markdown_Native_Schema_Introspection( $registry, database_name: $database_name );
+		$this->schema_introspection = new WP_Markdown_Native_Schema_Introspection( $registry, database_name: $database_name, session: $this->session );
 	}
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
@@ -99,6 +100,10 @@ private function execute_request( WP_Markdown_Query_Request $request ): WP_Markd
 		$this->correlated_subquery_cache = array();
 		$this->correlated_subquery_failure = null;
 		$this->statement_now = gmdate( 'Y-m-d H:i:s' );
+		$session_result = $this->session->execute( $request->sql() );
+		if ( null !== $session_result ) {
+			return $session_result;
+		}
 		$transaction_control = WP_Markdown_SQL_Classifier::transaction_control( $request->sql() );
 		if ( null !== $transaction_control ) {
 			return $this->execute_transaction_control( $transaction_control );
@@ -319,6 +324,7 @@ private function tableless_scalar_type( WP_Markdown_Native_Query_Scalar_Expressi
 	/** Release this logical connection's root-scoped advisory locks. */
 	public function close(): void {
 		$this->advisory_locks?->close();
+		$this->session->reset();
 	}
 
 	private function advisory_lock_query( string $sql ): ?WP_Markdown_Query_Result {
diff --git a/inc/native/class-wp-markdown-native-query-runtime.php b/inc/native/class-wp-markdown-native-query-runtime.php
index 90fc9df..d92b994 100644
--- a/inc/native/class-wp-markdown-native-query-runtime.php
+++ b/inc/native/class-wp-markdown-native-query-runtime.php
@@ -7,6 +7,7 @@
 
 require_once __DIR__ . '/../class-wp-markdown-canonical-option-path.php';
 require_once __DIR__ . '/class-wp-markdown-native-query-contracts.php';
+require_once __DIR__ . '/class-wp-markdown-native-sql-session.php';
 require_once __DIR__ . '/class-wp-markdown-native-query-schema.php';
 require_once __DIR__ . '/class-wp-markdown-native-schema-catalog.php';
 require_once __DIR__ . '/class-wp-markdown-native-sql-tokenizer.php';
@@ -253,8 +254,10 @@ public static function runtime(
 		?string $global_state_root = null,
 		?string $global_content_root = null,
 		?WP_Markdown_Native_Advisory_Locks $advisory_locks = null,
-		?string $transaction_state_root = null
+		?string $transaction_state_root = null,
+		?WP_Markdown_Native_SQL_Session $session = null
 	): WP_Markdown_Native_Query_Runtime {
+		$session ??= new WP_Markdown_Native_SQL_Session();
 		$state_root = self::materialize_state_root( $state_root );
 		if ( null !== $content_root ) {
 			$content_root = self::materialize_state_root( $content_root );
@@ -292,7 +295,7 @@ public static function runtime(
 			new WP_Markdown_Native_Query_Parser(),
 			new WP_Markdown_Native_Option_Mutation_Runtime( $state_root, new WP_Markdown_Native_Option_Mutation_Parser(), $transactions ),
 			new WP_Markdown_Native_Schema_Mutation_Runtime( $state_root, $registry, $transactions, $core_registrar, $temporary_tables ),
-			new WP_Markdown_Native_Table_Mutation_Runtime( $state_root, $registry, $parser, $transactions, $temporary_tables ),
+			new WP_Markdown_Native_Table_Mutation_Runtime( $state_root, $registry, $parser, $transactions, $temporary_tables, $session ),
 			$transactions,
 			new WP_Markdown_Native_Post_Mutation_Runtime(
 				$registry,
@@ -300,7 +303,8 @@ public static function runtime(
 				self::shared_storage( $content_root ?? $state_root, $multisite && $prefix === $resolved_base ),
 				$transactions,
 			),
-			advisory_locks: $advisory_locks ?? new WP_Markdown_Native_Advisory_Locks( $state_root )
+			advisory_locks: $advisory_locks ?? new WP_Markdown_Native_Advisory_Locks( $state_root ),
+			session: $session
 		);
 	}
 
@@ -647,7 +651,8 @@ final class WP_Markdown_Native_Prefix_Query_Runtime implements WP_Markdown_Query
 
 	public function __construct(
 		private string $state_root,
-		private string $content_root
+		private string $content_root,
+		private WP_Markdown_Native_SQL_Session $session = new WP_Markdown_Native_SQL_Session()
 	) {
 		$this->advisory_locks = new WP_Markdown_Native_Advisory_Locks( $state_root );
 	}
@@ -661,7 +666,8 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 				$prefix,
 				false,
 				$this->content_root,
-				advisory_locks: $this->advisory_locks
+				advisory_locks: $this->advisory_locks,
+				session: $this->session
 			);
 		}
 		return $this->runtimes[ $prefix ]->execute( $request );
@@ -669,6 +675,7 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 
 	public function close(): void {
 		$this->advisory_locks->close();
+		$this->session->reset();
 	}
 }
 
@@ -678,9 +685,11 @@ final class WP_Markdown_Native_WordPress_Query_Runtime implements WP_Markdown_Qu
 	private WP_Markdown_Native_Prefix_Query_Runtime $prefix_runtime;
 	/** @var array<string,WP_Markdown_Native_Multisite_Query_Runtime> */
 	private array $multisite_runtimes = array();
+	private WP_Markdown_Native_SQL_Session $session;
 
 	public function __construct( string $state_root, private string $base_prefix, string $content_root ) {
-		$this->prefix_runtime = new WP_Markdown_Native_Prefix_Query_Runtime( $state_root, $content_root );
+		$this->session = new WP_Markdown_Native_SQL_Session();
+		$this->prefix_runtime = new WP_Markdown_Native_Prefix_Query_Runtime( $state_root, $content_root, $this->session );
 		$this->state_root = $state_root;
 		$this->content_root = $content_root;
 	}
@@ -697,7 +706,7 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 			? $GLOBALS['wpdb']->base_prefix
 			: $this->base_prefix;
 		if ( ! isset( $this->multisite_runtimes[ $base_prefix ] ) ) {
-			$this->multisite_runtimes[ $base_prefix ] = new WP_Markdown_Native_Multisite_Query_Runtime( $this->state_root, $base_prefix, $this->content_root );
+			$this->multisite_runtimes[ $base_prefix ] = new WP_Markdown_Native_Multisite_Query_Runtime( $this->state_root, $base_prefix, $this->content_root, $this->session );
 		}
 		return $this->multisite_runtimes[ $base_prefix ]->execute( $request );
 	}
@@ -722,7 +731,8 @@ final class WP_Markdown_Native_Multisite_Query_Runtime implements WP_Markdown_Qu
 	public function __construct(
 		string $state_root,
 		private string $base_prefix,
-		string $content_root
+		string $content_root,
+		private WP_Markdown_Native_SQL_Session $session = new WP_Markdown_Native_SQL_Session()
 	) {
 		if ( 1 !== preg_match( '/^[A-Za-z0-9_]+$/D', $base_prefix ) ) {
 			throw new InvalidArgumentException( 'The base table prefix contains unsupported characters.' );
@@ -764,7 +774,8 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 					$this->state_root,
 					$this->content_root,
 					$this->advisory_locks,
-					$this->state_root
+					$this->state_root,
+					$this->session
 				);
 			} catch ( Throwable ) {
 				return WP_Markdown_Query_Result::failure(
@@ -781,6 +792,7 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 
 	public function close(): void {
 		$this->advisory_locks->close();
+		$this->session->reset();
 	}
 
 	private function is_scope_prefix( string $prefix ): bool {
diff --git a/inc/native/class-wp-markdown-native-schema-introspection.php b/inc/native/class-wp-markdown-native-schema-introspection.php
index 0230c4e..3deb3cc 100644
--- a/inc/native/class-wp-markdown-native-schema-introspection.php
+++ b/inc/native/class-wp-markdown-native-schema-introspection.php
@@ -230,7 +230,8 @@ final class WP_Markdown_Native_Schema_Introspection {
 	public function __construct(
 		private readonly WP_Markdown_Native_Table_Registry $registry,
 		private readonly WP_Markdown_Native_Schema_Introspection_Parser $parser = new WP_Markdown_Native_Schema_Introspection_Parser(),
-		private readonly ?string $database_name = null
+		private readonly ?string $database_name = null,
+		private readonly ?WP_Markdown_Native_SQL_Session $session = null
 	) {}
 
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
@@ -560,7 +561,7 @@ private function server_values( string $operation, ?string $pattern, array $name
 			? array(
 				'version' => WP_Markdown_Native_Schema_Catalog::SERVER_VERSION,
 				'version_comment' => 'Markdown Database Integration native engine',
-				'sql_mode' => '',
+				'sql_mode' => $this->session?->sql_mode() ?? '',
 				'character_set_server' => 'utf8mb4',
 				'collation_server' => 'utf8mb4_general_ci',
 				'foreign_key_checks' => 'ON',
diff --git a/inc/native/class-wp-markdown-native-sql-session.php b/inc/native/class-wp-markdown-native-sql-session.php
new file mode 100644
index 0000000..37e057f
--- /dev/null
+++ b/inc/native/class-wp-markdown-native-sql-session.php
@@ -0,0 +1,60 @@
+<?php
+/** SQL mode and statement diagnostics shared by one logical native connection. */
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+final class WP_Markdown_Native_SQL_Session {
+	private string $sql_mode = '';
+	private array $warnings = array();
+	private int $warning_count = 0;
+
+	public function sql_mode(): string { return $this->sql_mode; }
+
+	public function strict(): bool {
+		return in_array( 'STRICT_TRANS_TABLES', explode( ',', $this->sql_mode ), true ) || in_array( 'STRICT_ALL_TABLES', explode( ',', $this->sql_mode ), true );
+	}
+
+	public function reset(): void {
+		$this->sql_mode = '';
+		$this->warnings = array();
+		$this->warning_count = 0;
+	}
+
+	public function warn_missing_default( string $column ): void {
+		++$this->warning_count;
+		if ( count( $this->warnings ) < 64 ) {
+			$this->warnings[] = array( 'Level' => 'Warning', 'Code' => '1364', 'Message' => "Field '{$column}' doesn't have a default value" );
+		}
+	}
+
+	/** Handle supported session statements, otherwise start a new diagnostic area. */
+	public function execute( string $sql ): ?WP_Markdown_Query_Result {
+		if ( 1 === preg_match( '/^\s*SHOW\s+WARNINGS\s*;?\s*$/i', $sql ) ) {
+			return WP_Markdown_Query_Result::selected( $this->warnings, array(
+				array( 'name' => 'Level', 'table' => '', 'type' => 253 ),
+				array( 'name' => 'Code', 'table' => '', 'type' => 3 ),
+				array( 'name' => 'Message', 'table' => '', 'type' => 253 ),
+			) );
+		}
+		if ( 1 === preg_match( '/^\s*SELECT\s+(@@(?:SESSION\.)?warning_count)\s*;?\s*$/i', $sql, $match ) ) {
+			return WP_Markdown_Query_Result::selected( array( array( $match[1] => (string) $this->warning_count ) ), array( array( 'name' => $match[1], 'table' => '', 'type' => 8 ) ) );
+		}
+		$this->warnings = array();
+		$this->warning_count = 0;
+		if ( 1 === preg_match( '/^\s*SELECT\s+(@@(?:SESSION\.)?sql_mode)\s*;?\s*$/i', $sql, $match ) ) {
+			return WP_Markdown_Query_Result::selected( array( array( $match[1] => $this->sql_mode ) ), array( array( 'name' => $match[1], 'table' => '', 'type' => 253 ) ) );
+		}
+		if ( 1 !== preg_match( "/^\\s*SET\\s+(?:SESSION\\s+|@@(?:SESSION\\.)?)?sql_mode\\s*=\\s*'([A-Za-z_, ]*)'\\s*;?\\s*$/i", $sql, $match ) ) {
+			return null;
+		}
+		$modes = array_values( array_unique( array_filter( array_map( static fn( string $mode ): string => strtoupper( trim( $mode ) ), explode( ',', $match[1] ) ) ) ) );
+		$supported = array( 'STRICT_TRANS_TABLES', 'STRICT_ALL_TABLES', 'NO_ENGINE_SUBSTITUTION' );
+		if ( array_diff( $modes, $supported ) ) {
+			return WP_Markdown_Query_Result::failure( array( 'code' => 'markdown_db_native_unsupported_query', 'reason' => 'unsupported_sql_mode', 'message' => 'The requested SQL mode includes semantics not implemented by the native session.' ) );
+		}
+		$this->sql_mode = implode( ',', array_values( array_intersect( $supported, $modes ) ) );
+		return WP_Markdown_Query_Result::mutated( 0 );
+	}
+}
diff --git a/inc/native/class-wp-markdown-native-table-mutations.php b/inc/native/class-wp-markdown-native-table-mutations.php
index afcc90a..eb206f5 100644
--- a/inc/native/class-wp-markdown-native-table-mutations.php
+++ b/inc/native/class-wp-markdown-native-table-mutations.php
@@ -21,7 +21,8 @@ public function __construct(
 		private WP_Markdown_Native_Table_Registry $registry,
 		private WP_Markdown_Native_Table_Insert_Parser $parser = new WP_Markdown_Native_Table_Insert_Parser(),
 		private ?WP_Markdown_Native_Transaction_Journal $transactions = null,
-		private ?WP_Markdown_Native_Temporary_Tables $temporary_tables = null
+		private ?WP_Markdown_Native_Temporary_Tables $temporary_tables = null,
+		private WP_Markdown_Native_SQL_Session $session = new WP_Markdown_Native_SQL_Session()
 	) {
 		$root = realpath( $state_root );
 		if ( false === $root || ! is_dir( $root ) ) {
@@ -376,6 +377,25 @@ private function complete_row( array $provided, array $definition, array $rows,
 				$row[ $name ] = null;
 				continue;
 			}
+			if ( ! $this->session->strict() ) {
+				$type = strtolower( $column['type'] ?? '' );
+				$implicit = match ( $type ) {
+					'tinyint', 'smallint', 'mediumint', 'int', 'integer', 'bigint', 'decimal', 'numeric', 'float', 'double', 'real', 'year' => '0',
+					'char', 'varchar', 'tinytext', 'text', 'mediumtext', 'longtext', 'tinyblob', 'blob', 'mediumblob', 'longblob', 'varbinary' => '',
+					'date' => '0000-00-00',
+					'datetime', 'timestamp' => '0000-00-00 00:00:00',
+					'time' => '00:00:00',
+					default => null,
+				};
+				if ( null !== $implicit ) {
+					$row[ $name ] = $implicit;
+					$this->session->warn_missing_default( $name );
+					continue;
+				}
+			}
+			if ( $this->session->strict() ) {
+				return WP_Markdown_Query_Result::failure( array( 'code' => 1364, 'reason' => 'missing_required_column', 'message' => "Field '{$name}' doesn't have a default value" ) );
+			}
 			return $this->failure( 'missing_required_column', 'The INSERT omits a required column without a deterministic default.' );
 		}
 		return $row;
diff --git a/tests/smoke-native-sql-mode-defaults.php b/tests/smoke-native-sql-mode-defaults.php
new file mode 100644
index 0000000..46dc011
--- /dev/null
+++ b/tests/smoke-native-sql-mode-defaults.php
@@ -0,0 +1,43 @@
+<?php
+/** SQL-mode-sensitive implicit defaults use one logical connection across scopes. */
+declare( strict_types=1 );
+define( 'ABSPATH', __DIR__ . '/' );
+require_once __DIR__ . '/../inc/native/class-wp-markdown-native-query-runtime.php';
+
+$root = sys_get_temp_dir() . '/mdi-sql-mode-' . bin2hex( random_bytes( 6 ) );
+mkdir( $root, 0755 );
+$checks = array();
+try {
+	$runtime = WP_Markdown_Native_Runtime_Factory::runtime( $root );
+	$run = static fn( string $sql ): WP_Markdown_Query_Result => $runtime->execute( new WP_Markdown_Query_Request( $sql ) );
+	$created = $run( 'CREATE TABLE wp_defaults (id bigint unsigned NOT NULL AUTO_INCREMENT, payload longtext NOT NULL, amount int NOT NULL, optional_value varchar(20) NULL, explicit_value varchar(20) NOT NULL DEFAULT \'chosen\', PRIMARY KEY (id))' );
+	$inserted = $run( 'INSERT INTO wp_defaults (id) VALUES (1)' );
+	$warnings = $run( 'SHOW WARNINGS' );
+	$count = $run( 'SELECT @@warning_count' );
+	$row = $run( 'SELECT * FROM wp_defaults WHERE id = 1' )->corpus_result()['rows'][0] ?? null;
+	$checks['non-strict defaults preserve nullable and explicit defaults'] = $created->succeeded() && 1 === $inserted->return_value() && array( 'id' => '1', 'payload' => '', 'amount' => '0', 'optional_value' => null, 'explicit_value' => 'chosen' ) === $row;
+	$checks['implicit defaults report bounded MySQL warnings'] = 2 === $warnings->return_value() && '1364' === $warnings->corpus_result()['rows'][0]['Code'] && '2' === $count->corpus_result()['rows'][0]['@@warning_count'];
+	$set = $run( "SET SESSION sql_mode = 'strict_trans_tables,NO_ENGINE_SUBSTITUTION'" );
+	$mode = $run( 'SELECT @@SESSION.sql_mode' );
+	$variables = $run( "SHOW VARIABLES LIKE 'sql_mode'" );
+	$checks['session and SHOW introspection agree on supported mode'] = $set->succeeded() && 'STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION' === $mode->corpus_result()['rows'][0]['@@SESSION.sql_mode'] && 'STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION' === $variables->corpus_result()['rows'][0]['Value'];
+	$rejected = $run( 'INSERT INTO wp_defaults (id) VALUES (2)' );
+	$checks['strict omission fails with MySQL errno and no row'] = false === $rejected->return_value() && 1364 === $rejected->diagnostic()['code'] && 0 === $run( 'SELECT * FROM wp_defaults WHERE id = 2' )->return_value();
+	$invalid = $run( "SET sql_mode = 'ANSI_QUOTES'" );
+	$checks['unsupported mode fails without changing existing mode'] = ! $invalid->succeeded() && 'STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION' === $run( 'SELECT @@sql_mode' )->corpus_result()['rows'][0]['@@sql_mode'];
+	$run( "SET @@SESSION.sql_mode = ''" );
+	$checks['clearing strict mode restores implicit defaults'] = 1 === $run( 'INSERT INTO wp_defaults (id) VALUES (2)' )->return_value();
+	$multisite = WP_Markdown_Native_Runtime_Factory::multisite_runtime( $root );
+	$multisite->execute( new WP_Markdown_Query_Request( "SET sql_mode = 'STRICT_ALL_TABLES'", 'wp_' ) );
+	$site_mode = $multisite->execute( new WP_Markdown_Query_Request( 'SELECT @@sql_mode', 'wp_2_' ) );
+	$checks['blog switching shares mode but separate connections do not'] = 'STRICT_ALL_TABLES' === $site_mode->corpus_result()['rows'][0]['@@sql_mode'] && '' === $run( 'SELECT @@sql_mode' )->corpus_result()['rows'][0]['@@sql_mode'];
+	$multisite->close();
+	$checks['logical close resets SQL session mode'] = '' === $multisite->execute( new WP_Markdown_Query_Request( 'SELECT @@sql_mode', 'wp_' ) )->corpus_result()['rows'][0]['@@sql_mode'];
+} finally {
+	foreach ( new RecursiveIteratorIterator( new RecursiveDirectoryIterator( $root, FilesystemIterator::SKIP_DOTS ), RecursiveIteratorIterator::CHILD_FIRST ) as $entry ) {
+		$entry->isDir() ? rmdir( $entry->getPathname() ) : unlink( $entry->getPathname() );
+	}
+	rmdir( $root );
+}
+foreach ( $checks as $label => $passed ) { fwrite( $passed ? STDOUT : STDERR, ( $passed ? 'PASS: ' : 'FAIL: ' ) . $label . "\n" ); }
+exit( in_array( false, $checks, true ) ? 1 : 0 );
diff --git a/tests/smoke-native-table-insert.php b/tests/smoke-native-table-insert.php
index 4afeb76..5239f72 100644
--- a/tests/smoke-native-table-insert.php
+++ b/tests/smoke-native-table-insert.php
@@ -35,7 +35,9 @@ function mdi_native_insert_remove_tree( string $root ): void {
 $first = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO `wp_plugin_jobs` (`job_id`, `hook`, `payload`) VALUES (0, 'first_job', NULL)" ) );
 $second = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_plugin_jobs (job_id, hook, priority) VALUES (8, 'second_job', 2);" ) );
 $duplicate = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_plugin_jobs (job_id, hook) VALUES (8, 'duplicate_job')" ) );
+$runtime->execute( new WP_Markdown_Query_Request( "SET sql_mode = 'STRICT_TRANS_TABLES'" ) );
 $missing = $runtime->execute( new WP_Markdown_Query_Request( 'INSERT INTO wp_plugin_jobs (priority) VALUES (3)' ) );
+$runtime->execute( new WP_Markdown_Query_Request( "SET sql_mode = ''" ) );
 $multi = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_plugin_jobs (hook) VALUES ('third'); INSERT INTO wp_plugin_jobs (hook) VALUES ('fourth')" ) );
 $selected = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT * FROM wp_plugin_jobs ORDER BY job_id ASC' ) );
 $reloaded = WP_Markdown_Native_Runtime_Factory::runtime( $root )->execute( new WP_Markdown_Query_Request( "SELECT hook, priority FROM wp_plugin_jobs WHERE job_id IN (1, 8) ORDER BY job_id ASC" ) );
@@ -66,7 +68,7 @@ function mdi_native_insert_remove_tree( string $root ): void {
 	'persisted rows retain schema order and typed values' => array( '1', '8' ) === array_map( static fn( object $row ): string => $row->job_id, $selected->wpdb_state()['last_result'] )
 		&& '10' === $selected->wpdb_state()['last_result'][0]->priority
 		&& null === $selected->wpdb_state()['last_result'][0]->payload,
-	'unique conflicts and missing required columns fail without mutation' => false === $duplicate->return_value()
+	'unique conflicts and strict-mode missing required columns fail without mutation' => false === $duplicate->return_value()
 		&& 'duplicate_key' === ( $duplicate->diagnostic()['reason'] ?? null )
 		&& false === $missing->return_value()
 		&& 'missing_required_column' === ( $missing->diagnostic()['reason'] ?? null )

From 904d4277397c81911280ab2472388aa6bf6f2b2e Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 16:48:14 -0400
Subject: [PATCH 47/53] fix(native): retain strict missing-default diagnostics

---
 .../class-wp-markdown-native-sql-session.php      |  4 ++--
 .../class-wp-markdown-native-table-mutations.php  | 15 ++++++++++++---
 tests/smoke-native-sql-mode-defaults.php          |  2 ++
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-sql-session.php b/inc/native/class-wp-markdown-native-sql-session.php
index 37e057f..1e2015e 100644
--- a/inc/native/class-wp-markdown-native-sql-session.php
+++ b/inc/native/class-wp-markdown-native-sql-session.php
@@ -22,10 +22,10 @@ public function reset(): void {
 		$this->warning_count = 0;
 	}
 
-	public function warn_missing_default( string $column ): void {
+	public function warn_missing_default( string $column, bool $error = false ): void {
 		++$this->warning_count;
 		if ( count( $this->warnings ) < 64 ) {
-			$this->warnings[] = array( 'Level' => 'Warning', 'Code' => '1364', 'Message' => "Field '{$column}' doesn't have a default value" );
+			$this->warnings[] = array( 'Level' => $error ? 'Error' : 'Warning', 'Code' => '1364', 'Message' => "Field '{$column}' doesn't have a default value" );
 		}
 	}
 
diff --git a/inc/native/class-wp-markdown-native-table-mutations.php b/inc/native/class-wp-markdown-native-table-mutations.php
index eb206f5..bacd63f 100644
--- a/inc/native/class-wp-markdown-native-table-mutations.php
+++ b/inc/native/class-wp-markdown-native-table-mutations.php
@@ -331,6 +331,18 @@ private function complete_row( array $provided, array $definition, array $rows,
 		if ( array_diff_key( $provided, $definition['columns'] ) ) {
 			return $this->failure( 'unsupported_column', 'The INSERT references an undeclared column.' );
 		}
+		if ( $this->session->strict() ) {
+			$missing = array();
+			foreach ( $definition['columns'] as $name => $column ) {
+				if ( ! array_key_exists( $name, $provided ) && empty( $column['auto_increment'] ) && empty( $column['nullable'] ) && null === ( $column['default'] ?? null ) ) {
+					$missing[] = $name;
+					$this->session->warn_missing_default( $name, true );
+				}
+			}
+			if ( array() !== $missing ) {
+				return WP_Markdown_Query_Result::failure( array( 'code' => 1364, 'reason' => 'missing_required_column', 'message' => "Field '{$missing[0]}' doesn't have a default value" ) );
+			}
+		}
 		$row = array();
 		foreach ( $definition['columns'] as $name => $column ) {
 			$generate_identity = true === ( $column['auto_increment'] ?? false )
@@ -393,9 +405,6 @@ private function complete_row( array $provided, array $definition, array $rows,
 					continue;
 				}
 			}
-			if ( $this->session->strict() ) {
-				return WP_Markdown_Query_Result::failure( array( 'code' => 1364, 'reason' => 'missing_required_column', 'message' => "Field '{$name}' doesn't have a default value" ) );
-			}
 			return $this->failure( 'missing_required_column', 'The INSERT omits a required column without a deterministic default.' );
 		}
 		return $row;
diff --git a/tests/smoke-native-sql-mode-defaults.php b/tests/smoke-native-sql-mode-defaults.php
index 46dc011..3193089 100644
--- a/tests/smoke-native-sql-mode-defaults.php
+++ b/tests/smoke-native-sql-mode-defaults.php
@@ -22,6 +22,8 @@
 	$variables = $run( "SHOW VARIABLES LIKE 'sql_mode'" );
 	$checks['session and SHOW introspection agree on supported mode'] = $set->succeeded() && 'STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION' === $mode->corpus_result()['rows'][0]['@@SESSION.sql_mode'] && 'STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION' === $variables->corpus_result()['rows'][0]['Value'];
 	$rejected = $run( 'INSERT INTO wp_defaults (id) VALUES (2)' );
+	$errors = $run( 'SHOW WARNINGS' );
+	$checks['strict omissions retain every missing-default error'] = 2 === $errors->return_value() && 'Error' === $errors->corpus_result()['rows'][0]['Level'] && '1364' === $errors->corpus_result()['rows'][1]['Code'];
 	$checks['strict omission fails with MySQL errno and no row'] = false === $rejected->return_value() && 1364 === $rejected->diagnostic()['code'] && 0 === $run( 'SELECT * FROM wp_defaults WHERE id = 2' )->return_value();
 	$invalid = $run( "SET sql_mode = 'ANSI_QUOTES'" );
 	$checks['unsupported mode fails without changing existing mode'] = ! $invalid->succeeded() && 'STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION' === $run( 'SELECT @@sql_mode' )->corpus_result()['rows'][0]['@@sql_mode'];

From 243b06f3f5c2338d42cc8dcfddc0c1eef449e3ff Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 17:10:32 -0400
Subject: [PATCH 48/53] fix(native): bind unqualified joined columns by schema

---
 ...lass-wp-markdown-native-query-executor.php |   2 +-
 .../class-wp-markdown-native-query-parser.php | 157 ++++++++++++------
 tests/smoke-native-join-query.php             |  13 +-
 3 files changed, 120 insertions(+), 52 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index b21d314..5f7ef1c 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -178,7 +178,7 @@ private function execute_unlocked_request( WP_Markdown_Query_Request $request ):
 		}
 		$start = WP_Markdown_Operation_Profile::begin();
 		try {
-			$plan = $this->parser->parse( $request->sql() );
+			$plan = $this->parser->parse( $request->sql(), fn( string $table ): array => array_keys( $this->registry->definition( $table )['columns'] ?? array() ) );
 		} finally {
 			WP_Markdown_Operation_Profile::end( 'select_parse', $start );
 		}
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index 666ce5b..1a4c16a 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -10,14 +10,14 @@ public function __construct(
 		private WP_Markdown_Native_SQL_Tokenizer $tokenizer = new WP_Markdown_Native_SQL_Tokenizer()
 	) {}
 
-	public function parse( string $sql ): WP_Markdown_Native_Query_Plan|WP_Markdown_Native_Found_Rows_Plan|WP_Markdown_Query_Result {
+	public function parse( string $sql, ?callable $table_columns = null ): WP_Markdown_Native_Query_Plan|WP_Markdown_Native_Found_Rows_Plan|WP_Markdown_Query_Result {
 		self::trace_runtime_phase( 'parser', $sql );
 		$ast = $this->parse_ast( $sql );
 		if ( $ast instanceof WP_Markdown_Query_Result ) {
 			return $ast;
 		}
 		try {
-			return $this->lower( $ast );
+			return $this->lower( $ast, array(), $table_columns );
 		} catch ( WP_Markdown_Native_SQL_Parse_Error $error ) {
 			return $this->failure( $error->reason(), $error->getMessage(), $error->sql_offset() );
 		}
@@ -113,7 +113,7 @@ public function parse_ast( string $sql ): WP_Markdown_Native_SQL_Select|WP_Markd
 	}
 
 	/** @param array<string,true> $outer_sources */
-	public function lower( WP_Markdown_Native_SQL_Select|WP_Markdown_Native_SQL_Found_Rows $ast, array $outer_sources = array() ): WP_Markdown_Native_Query_Plan|WP_Markdown_Native_Found_Rows_Plan|WP_Markdown_Query_Result {
+	public function lower( WP_Markdown_Native_SQL_Select|WP_Markdown_Native_SQL_Found_Rows $ast, array $outer_sources = array(), ?callable $table_columns = null ): WP_Markdown_Native_Query_Plan|WP_Markdown_Native_Found_Rows_Plan|WP_Markdown_Query_Result {
 		if ( $ast instanceof WP_Markdown_Native_SQL_Found_Rows ) {
 			return new WP_Markdown_Native_Found_Rows_Plan();
 		}
@@ -123,6 +123,7 @@ public function lower( WP_Markdown_Native_SQL_Select|WP_Markdown_Native_SQL_Foun
 			return $this->failure( 'unsupported_select_modifier', 'DISTINCT requires a row projection.', $ast->table()->sql_offset() );
 		}
 		$base_source = array() === $ast->joins() ? null : ( $ast->alias()?->name() ?? $ast->table()->name() );
+		$bindings = null === $table_columns || null === $base_source ? array() : $this->column_bindings( $ast, $table_columns );
 		$flat_source = array() === $ast->joins() ? ( $ast->alias()?->name() ?? $ast->table()->name() ) : null;
 		$child_outer_sources = $outer_sources;
 		$child_outer_sources[ $ast->alias()?->name() ?? $ast->table()->name() ] = true;
@@ -132,21 +133,21 @@ public function lower( WP_Markdown_Native_SQL_Select|WP_Markdown_Native_SQL_Foun
 			: array_map( static fn( WP_Markdown_Native_SQL_Identifier $column ): string => $column->name(), $ast->projection() );
 		$scalar_projection = array_map(
 			fn( array $scalar ): array => array(
-				'expression' => $this->lower_scalar_expression( $scalar['expression'], $base_source, $flat_source ),
+				'expression' => $this->lower_scalar_expression( $scalar['expression'], $base_source, $flat_source, $bindings ),
 				'alias'      => $scalar['alias'],
 				'position'   => $scalar['position'],
 			),
 			$ast->scalar_projection()
 		);
-		$scalar_predicates = array_map( fn( WP_Markdown_Native_SQL_Scalar_Predicate $predicate ): WP_Markdown_Native_Query_Scalar_Predicate => $this->lower_scalar_predicate( $predicate, $base_source, $flat_source ), $ast->scalar_predicates() );
-		$boolean_predicate = null === $ast->boolean_predicate() ? null : new WP_Markdown_Native_Query_Boolean_Predicate( array_map( function ( array $group ) use ( $base_source, $flat_source, $child_outer_sources ): array {
-			return array_map( function ( WP_Markdown_Native_SQL_Predicate|WP_Markdown_Native_SQL_Scalar_Predicate|WP_Markdown_Native_SQL_Subquery_Predicate $predicate ) use ( $base_source, $flat_source, $child_outer_sources ): WP_Markdown_Native_Query_Predicate|WP_Markdown_Native_Query_Scalar_Predicate|WP_Markdown_Native_Query_Subquery {
-				if ( $predicate instanceof WP_Markdown_Native_SQL_Scalar_Predicate ) { return $this->lower_scalar_predicate( $predicate, $base_source, $flat_source ); }
-				if ( $predicate instanceof WP_Markdown_Native_SQL_Subquery_Predicate ) { return $this->lower_subquery( $predicate, $child_outer_sources ); }
-				return $this->lower_predicate( $predicate, $base_source );
+		$scalar_predicates = array_map( fn( WP_Markdown_Native_SQL_Scalar_Predicate $predicate ): WP_Markdown_Native_Query_Scalar_Predicate => $this->lower_scalar_predicate( $predicate, $base_source, $flat_source, $bindings ), $ast->scalar_predicates() );
+		$boolean_predicate = null === $ast->boolean_predicate() ? null : new WP_Markdown_Native_Query_Boolean_Predicate( array_map( function ( array $group ) use ( $base_source, $flat_source, $child_outer_sources, $bindings, $table_columns ): array {
+			return array_map( function ( WP_Markdown_Native_SQL_Predicate|WP_Markdown_Native_SQL_Scalar_Predicate|WP_Markdown_Native_SQL_Subquery_Predicate $predicate ) use ( $base_source, $flat_source, $child_outer_sources, $bindings, $table_columns ): WP_Markdown_Native_Query_Predicate|WP_Markdown_Native_Query_Scalar_Predicate|WP_Markdown_Native_Query_Subquery {
+				if ( $predicate instanceof WP_Markdown_Native_SQL_Scalar_Predicate ) { return $this->lower_scalar_predicate( $predicate, $base_source, $flat_source, $bindings ); }
+				if ( $predicate instanceof WP_Markdown_Native_SQL_Subquery_Predicate ) { return $this->lower_subquery( $predicate, $child_outer_sources, $table_columns, $bindings ); }
+				return $this->lower_predicate( $predicate, $base_source, $bindings );
 			}, $group );
 		}, $ast->boolean_predicate()->groups() ) );
-		$scalar_having = array_map( fn( WP_Markdown_Native_SQL_Scalar_Predicate $predicate ): WP_Markdown_Native_Query_Scalar_Predicate => $this->lower_scalar_predicate( $predicate, null, $flat_source ), $ast->scalar_having() );
+		$scalar_having = array_map( fn( WP_Markdown_Native_SQL_Scalar_Predicate $predicate ): WP_Markdown_Native_Query_Scalar_Predicate => $this->lower_scalar_predicate( $predicate, null, $flat_source, $bindings ), $ast->scalar_having() );
 		$seen = array();
 		foreach ( $ast->projection() as $column ) {
 			$key = ( $column->qualifier() ?? '' ) . '.' . $column->name();
@@ -168,26 +169,26 @@ public function lower( WP_Markdown_Native_SQL_Select|WP_Markdown_Native_SQL_Foun
 
 		$predicates = array();
 		$subqueries = array();
-		foreach ( $ast->subqueries() as $subquery_predicate ) { $subqueries[] = $this->lower_subquery( $subquery_predicate, $child_outer_sources ); }
+		foreach ( $ast->subqueries() as $subquery_predicate ) { $subqueries[] = $this->lower_subquery( $subquery_predicate, $child_outer_sources, $table_columns, $bindings ); }
 		foreach ( $ast->predicates() as $predicate ) {
-			$predicates[] = $this->lower_predicate( $predicate, $base_source );
+			$predicates[] = $this->lower_predicate( $predicate, $base_source, $bindings );
 		}
 		$joins = array();
 		foreach ( $ast->joins() as $join ) {
-			$join_derived = null === $join->derived() ? null : $this->lower( $join->derived() );
+			$join_derived = null === $join->derived() ? null : $this->lower( $join->derived(), array(), $table_columns );
 			if ( null !== $join_derived && ! $join_derived instanceof WP_Markdown_Native_Query_Plan ) {
 				return $join_derived;
 			}
 			$joins[] = new WP_Markdown_Native_Query_Join(
 				$join->table()->name(),
 				$join->alias()->name(),
-				$join->left()?->qualifier(),
+				$this->column_source( $join->left(), null, $bindings ),
 				$join->left()?->name(),
-				$join->right()?->qualifier(),
+				$this->column_source( $join->right(), null, $bindings ),
 				$join->right()?->name(),
 				$join->is_outer(),
 				array_map(
-					fn( WP_Markdown_Native_SQL_Predicate $predicate ): WP_Markdown_Native_Query_Predicate => $this->lower_predicate( $predicate, $join->alias()->name() ),
+					fn( WP_Markdown_Native_SQL_Predicate $predicate ): WP_Markdown_Native_Query_Predicate => $this->lower_predicate( $predicate, $join->alias()->name(), $bindings ),
 					$join->on_predicates()
 				),
 				$join_derived
@@ -228,33 +229,33 @@ public function lower( WP_Markdown_Native_SQL_Select|WP_Markdown_Native_SQL_Foun
 			fn( array $item ): array => array(
 				'column'     => $item['column']->name(),
 				'descending' => $item['descending'],
-				'source'     => in_array( $item['column']->name(), $aggregate_aliases, true ) ? null : ( $item['column']->qualifier() ?? $base_source ),
+				'source'     => in_array( $item['column']->name(), $aggregate_aliases, true ) ? null : $this->column_source( $item['column'], $base_source, $bindings ),
 				'numeric'    => $item['numeric'] ?? false,
 				'like'       => $item['like'] ?? null,
 				'field'      => $item['field'] ?? null,
 				'case'       => null === ( $item['case'] ?? null ) ? null : array(
 					'branches' => array_map(
 						fn( array $branch ): array => array(
-							'predicates' => array_map( fn( WP_Markdown_Native_SQL_Predicate $predicate ): WP_Markdown_Native_Query_Predicate => $this->lower_predicate( $predicate, $base_source ), $branch['predicates'] ),
+							'predicates' => array_map( fn( WP_Markdown_Native_SQL_Predicate $predicate ): WP_Markdown_Native_Query_Predicate => $this->lower_predicate( $predicate, $base_source, $bindings ), $branch['predicates'] ),
 							'value'      => $branch['value'],
 						),
 						$item['case']['branches']
 					),
 					'else' => $item['case']['else'],
 				),
-				'expression' => null === ( $item['expression'] ?? null ) ? null : $this->lower_scalar_expression( $item['expression'], $base_source, $flat_source ),
+				'expression' => null === ( $item['expression'] ?? null ) ? null : $this->lower_scalar_expression( $item['expression'], $base_source, $flat_source, $bindings ),
 			),
 			$ast->orders()
 		);
 		$having = array_map( fn( WP_Markdown_Native_SQL_Predicate $predicate ): WP_Markdown_Native_Query_Predicate => $this->lower_predicate( $predicate, null ), $ast->having() );
 		$union = null;
 		if ( null !== $ast->union() ) {
-			$union = $this->lower( $ast->union() );
+			$union = $this->lower( $ast->union(), $outer_sources, $table_columns );
 			if ( ! $union instanceof WP_Markdown_Native_Query_Plan ) {
 				return $union;
 			}
 		}
-		$derived = null === $ast->derived() ? null : $this->lower( $ast->derived() );
+		$derived = null === $ast->derived() ? null : $this->lower( $ast->derived(), array(), $table_columns );
 		if ( null !== $derived && ! $derived instanceof WP_Markdown_Native_Query_Plan ) {
 			return $derived;
 		}
@@ -266,7 +267,7 @@ public function lower( WP_Markdown_Native_SQL_Select|WP_Markdown_Native_SQL_Foun
 			$ast->limit() ?? PHP_INT_MAX,
 			$ast->counts_all(),
 			$ast->alias()?->name(),
-			array_map( static fn( WP_Markdown_Native_SQL_Identifier $column ): ?string => $column->qualifier() ?? $base_source, $ast->projection() ),
+			array_map( fn( WP_Markdown_Native_SQL_Identifier $column ): ?string => $this->column_source( $column, $base_source, $bindings ), $ast->projection() ),
 			$joins,
 			$ast->calculates_found_rows(),
 			$ast->order_descending(),
@@ -277,10 +278,10 @@ public function lower( WP_Markdown_Native_SQL_Select|WP_Markdown_Native_SQL_Foun
 			$ast->is_contradiction(),
 			$ast->group_by()?->name(),
 			array_map(
-				static fn( array $aggregate ): array => array(
+				fn( array $aggregate ): array => array(
 					'function' => $aggregate['function'],
 					'column'   => $aggregate['column']?->name(),
-					'source'   => $aggregate['column']?->qualifier() ?? $base_source,
+					'source'   => $this->column_source( $aggregate['column'], $base_source, $bindings ),
 					'alias'    => $aggregate['alias'],
 					'distinct' => $aggregate['distinct'] ?? false,
 				),
@@ -293,28 +294,89 @@ public function lower( WP_Markdown_Native_SQL_Select|WP_Markdown_Native_SQL_Foun
 			$union,
 			$scalar_predicates,
 			$scalar_having,
-			null === $ast->group_expression() ? null : $this->lower_scalar_expression( $ast->group_expression(), $base_source, $flat_source ),
+			null === $ast->group_expression() ? null : $this->lower_scalar_expression( $ast->group_expression(), $base_source, $flat_source, $bindings ),
 			$boolean_predicate,
 			$derived,
 			$ast->union_all(),
 			array_map( fn( array $item ): array => array( 'column' => $item['column']->name(), 'descending' => $item['descending'], 'numeric' => str_starts_with( $item['column']->name(), '__union_ordinal_' ) ), $ast->union_orders() ),
 			$ast->union_limit(),
 			$ast->union_limit_offset(),
-			array_map( fn( WP_Markdown_Native_SQL_Scalar_Expression $expression ): WP_Markdown_Native_Query_Scalar_Expression => $this->lower_scalar_expression( $expression, $base_source, $flat_source ), $ast->group_expressions() ),
+			array_map( fn( WP_Markdown_Native_SQL_Scalar_Expression $expression ): WP_Markdown_Native_Query_Scalar_Expression => $this->lower_scalar_expression( $expression, $base_source, $flat_source, $bindings ), $ast->group_expressions() ),
 			$ast->index_hints()
 		);
 	}
 
+	/** Resolve unqualified identifiers only when their source schemas are known. */
+	private function column_bindings( WP_Markdown_Native_SQL_Select $ast, callable $table_columns ): array {
+		$sources = array( $ast->alias()?->name() ?? $ast->table()->name() => $this->source_columns( $ast->table()->name(), $ast->derived(), $table_columns ) );
+		$join_scopes = array();
+		foreach ( $ast->joins() as $join ) {
+			$sources[ $join->alias()->name() ] = $this->source_columns( $join->table()->name(), $join->derived(), $table_columns );
+			foreach ( $join->on_predicates() as $predicate ) {
+				foreach ( $this->predicate_columns( $predicate ) as $column ) {
+					$join_scopes[ spl_object_id( $column ) ] = $sources;
+				}
+			}
+		}
+		$aliases = array_merge( array_column( $ast->scalar_projection(), 'alias' ), array_column( $ast->aggregates(), 'alias' ) );
+		$order_aliases = array();
+		foreach ( $ast->orders() as $order ) {
+			if ( null === $order['column']->qualifier() && in_array( $order['column']->name(), $aliases, true ) ) {
+				$order_aliases[ spl_object_id( $order['column'] ) ] = true;
+			}
+		}
+		$bindings = array();
+		foreach ( $this->referenced_columns( $ast ) as $column ) {
+			if ( null !== $column->qualifier() || '*' === $column->name() || isset( $order_aliases[ spl_object_id( $column ) ] ) ) {
+				continue;
+			}
+			$owners = array_keys( array_filter( $join_scopes[ spl_object_id( $column ) ] ?? $sources, static fn( array $columns ): bool => in_array( $column->name(), $columns, true ) ) );
+			if ( 1 < count( $owners ) ) {
+				throw new WP_Markdown_Native_SQL_Parse_Error( 'ambiguous_column', $column->sql_offset(), 'The unqualified column belongs to more than one query source.' );
+			}
+			if ( 1 === count( $owners ) ) {
+				$bindings[ spl_object_id( $column ) ] = $owners[0];
+			}
+		}
+		return $bindings;
+	}
+
+	/** Derived sources expose their projected names, not their underlying tables. */
+	private function source_columns( string $table, ?WP_Markdown_Native_SQL_Select $derived, callable $table_columns ): array {
+		if ( null === $derived ) {
+			return $table_columns( $table ) ?? array();
+		}
+		if ( $derived->selects_all() ) {
+			return $this->source_columns( $derived->table()->name(), $derived->derived(), $table_columns );
+		}
+		$columns = array();
+		$inner_sources = array( $derived->alias()?->name() ?? $derived->table()->name() => array( $derived->table()->name(), $derived->derived() ) );
+		foreach ( $derived->joins() as $join ) { $inner_sources[ $join->alias()->name() ] = array( $join->table()->name(), $join->derived() ); }
+		foreach ( $derived->projection() as $column ) {
+			if ( '*' === $column->name() && isset( $inner_sources[ $column->qualifier() ] ) ) {
+				$source = $inner_sources[ $column->qualifier() ];
+				$columns = array_merge( $columns, $this->source_columns( $source[0], $source[1], $table_columns ) );
+			} else {
+				$columns[] = $column->name();
+			}
+		}
+		return array_merge( $columns, array_column( $derived->scalar_projection(), 'alias' ), array_column( $derived->aggregates(), 'alias' ) );
+	}
+
+	private function column_source( ?WP_Markdown_Native_SQL_Identifier $column, ?string $fallback, array $bindings ): ?string {
+		return null === $column ? $fallback : ( $column->qualifier() ?? $bindings[ spl_object_id( $column ) ] ?? $fallback );
+	}
+
 	/** @param array<string,true> $outer_sources */
-	private function lower_subquery( WP_Markdown_Native_SQL_Subquery_Predicate $predicate, array $outer_sources = array() ): WP_Markdown_Native_Query_Subquery {
-		$subquery = $this->lower( $predicate->query(), $outer_sources );
+	private function lower_subquery( WP_Markdown_Native_SQL_Subquery_Predicate $predicate, array $outer_sources = array(), ?callable $table_columns = null, array $bindings = array() ): WP_Markdown_Native_Query_Subquery {
+		$subquery = $this->lower( $predicate->query(), $outer_sources, $table_columns );
 		if ( ! $subquery instanceof WP_Markdown_Native_Query_Plan ) {
 			throw new WP_Markdown_Native_SQL_Parse_Error( 'unsupported_subquery_shape', $predicate->column()?->sql_offset() ?? 0, 'mdi-native could not lower the requested subquery.' );
 		}
-		return new WP_Markdown_Native_Query_Subquery( $predicate->operator(), $predicate->column()?->name(), $subquery, $predicate->column()?->qualifier() );
+		return new WP_Markdown_Native_Query_Subquery( $predicate->operator(), $predicate->column()?->name(), $subquery, $this->column_source( $predicate->column(), null, $bindings ) );
 	}
 
-	private function lower_predicate( WP_Markdown_Native_SQL_Predicate $predicate, ?string $base_source = null ): WP_Markdown_Native_Query_Predicate {
+	private function lower_predicate( WP_Markdown_Native_SQL_Predicate $predicate, ?string $base_source = null, array $bindings = array() ): WP_Markdown_Native_Query_Predicate {
 		$values = array_map( static fn( WP_Markdown_Native_SQL_Literal $literal ): int|string => $literal->value(), $predicate->values() );
 		if ( 'IN' === $predicate->operator() || 'NOT IN' === $predicate->operator() ) {
 			$values = array_values( array_unique( $values, SORT_REGULAR ) );
@@ -323,40 +385,41 @@ private function lower_predicate( WP_Markdown_Native_SQL_Predicate $predicate, ?
 			$predicate->column()->name(),
 			$predicate->operator(),
 			$values,
-			$predicate->column()->qualifier() ?? $base_source,
-			array_map( fn( WP_Markdown_Native_SQL_Predicate $alternative ): WP_Markdown_Native_Query_Predicate => $this->lower_predicate( $alternative, $base_source ), $predicate->any() ),
+			$this->column_source( $predicate->column(), $base_source, $bindings ),
+			array_map( fn( WP_Markdown_Native_SQL_Predicate $alternative ): WP_Markdown_Native_Query_Predicate => $this->lower_predicate( $alternative, $base_source, $bindings ), $predicate->any() ),
 			$predicate->cast(),
 			$predicate->comparison()?->name(),
-			$predicate->comparison()?->qualifier()
+			$this->column_source( $predicate->comparison(), null, $bindings )
 		);
 	}
 
-	private function lower_scalar_expression( WP_Markdown_Native_SQL_Scalar_Expression $expression, ?string $base_source, ?string $flat_source = null ): WP_Markdown_Native_Query_Scalar_Expression {
+	private function lower_scalar_expression( WP_Markdown_Native_SQL_Scalar_Expression $expression, ?string $base_source, ?string $flat_source = null, array $bindings = array() ): WP_Markdown_Native_Query_Scalar_Expression {
+		$source = $this->column_source( $expression->identifier(), $base_source, $bindings );
 		return new WP_Markdown_Native_Query_Scalar_Expression(
 			$expression->kind(),
 			$expression->identifier()?->name(),
 			$expression->literal(),
 			array_map(
-				fn( WP_Markdown_Native_SQL_Scalar_Expression $argument ): WP_Markdown_Native_Query_Scalar_Expression => $this->lower_scalar_expression( $argument, $base_source, $flat_source ),
+				fn( WP_Markdown_Native_SQL_Scalar_Expression $argument ): WP_Markdown_Native_Query_Scalar_Expression => $this->lower_scalar_expression( $argument, $base_source, $flat_source, $bindings ),
 				$expression->arguments()
 			),
 			array_map(
 				fn( array $branch ): array => array(
 					'predicates' => array_map(
-						fn( WP_Markdown_Native_SQL_Predicate $predicate ): WP_Markdown_Native_Query_Predicate => $this->lower_predicate( $predicate, $base_source ),
+						fn( WP_Markdown_Native_SQL_Predicate $predicate ): WP_Markdown_Native_Query_Predicate => $this->lower_predicate( $predicate, $base_source, $bindings ),
 						$branch['predicates']
 					),
-					'value' => $this->lower_scalar_expression( $branch['value'], $base_source, $flat_source ),
+					'value' => $this->lower_scalar_expression( $branch['value'], $base_source, $flat_source, $bindings ),
 			),
 			$expression->branches()
 		),
-			null === $expression->else() ? null : $this->lower_scalar_expression( $expression->else(), $base_source, $flat_source ),
-			$flat_source === ( $expression->identifier()?->qualifier() ?? $base_source ) ? null : ( $expression->identifier()?->qualifier() ?? $base_source )
+			null === $expression->else() ? null : $this->lower_scalar_expression( $expression->else(), $base_source, $flat_source, $bindings ),
+			$flat_source === $source ? null : $source
 		);
 	}
 
-	private function lower_scalar_predicate( WP_Markdown_Native_SQL_Scalar_Predicate $predicate, ?string $base_source, ?string $flat_source = null ): WP_Markdown_Native_Query_Scalar_Predicate {
-		return new WP_Markdown_Native_Query_Scalar_Predicate( $this->lower_scalar_expression( $predicate->left(), $base_source, $flat_source ), $predicate->operator(), $this->lower_scalar_expression( $predicate->right(), $base_source, $flat_source ) );
+	private function lower_scalar_predicate( WP_Markdown_Native_SQL_Scalar_Predicate $predicate, ?string $base_source, ?string $flat_source = null, array $bindings = array() ): WP_Markdown_Native_Query_Scalar_Predicate {
+		return new WP_Markdown_Native_Query_Scalar_Predicate( $this->lower_scalar_expression( $predicate->left(), $base_source, $flat_source, $bindings ), $predicate->operator(), $this->lower_scalar_expression( $predicate->right(), $base_source, $flat_source, $bindings ) );
 	}
 
 	/** @return array<int,WP_Markdown_Native_SQL_Identifier> */
@@ -382,7 +445,7 @@ private function referenced_columns( WP_Markdown_Native_SQL_Select $ast ): array
 			$columns = array_merge( $columns, $ast->boolean_predicate()->columns() );
 		}
 		foreach ( $ast->scalar_having() as $predicate ) { $columns = array_merge( $columns, $predicate->columns() ); }
-		if ( null !== $ast->group_expression() ) { $columns = array_merge( $columns, $ast->group_expression()->columns() ); }
+		foreach ( $ast->group_expressions() as $expression ) { $columns = array_merge( $columns, $expression->columns() ); }
 		foreach ( $ast->orders() as $item ) {
 			if ( null !== ( $item['expression'] ?? null ) ) { $columns = array_merge( $columns, $item['expression']->columns() ); continue; }
 			if ( null === ( $item['case'] ?? null ) ) {
@@ -413,6 +476,7 @@ private function referenced_columns( WP_Markdown_Native_SQL_Select $ast ): array
 	/** @return array<int,WP_Markdown_Native_SQL_Identifier> */
 	private function predicate_columns( WP_Markdown_Native_SQL_Predicate $predicate ): array {
 		$columns = array( $predicate->column() );
+		if ( null !== $predicate->comparison() ) { $columns[] = $predicate->comparison(); }
 		foreach ( $predicate->any() as $alternative ) {
 			$columns = array_merge( $columns, $this->predicate_columns( $alternative ) );
 		}
@@ -605,13 +669,6 @@ private function select( bool $nested ): WP_Markdown_Native_SQL_Select|WP_Markdo
 			}
 			$left = null === $equality ? null : $equality->column();
 			$right = null === $equality ? null : $equality->comparison();
-			$base_source = $alias ?? $table;
-			if ( null !== $left && null === $left->qualifier() ) {
-				$left = new WP_Markdown_Native_SQL_Identifier( $left->name(), $left->sql_offset(), $base_source->name() );
-			}
-			if ( null !== $right && null === $right->qualifier() ) {
-				$right = new WP_Markdown_Native_SQL_Identifier( $right->name(), $right->sql_offset(), $base_source->name() );
-			}
 			if ( null !== $equality_index && null !== $left && null !== $right ) {
 				$on_predicates[ $equality_index ] = new WP_Markdown_Native_SQL_Predicate( $left, '=', array(), array(), null, $right );
 			}
diff --git a/tests/smoke-native-join-query.php b/tests/smoke-native-join-query.php
index 128d6a3..26d8586 100644
--- a/tests/smoke-native-join-query.php
+++ b/tests/smoke-native-join-query.php
@@ -91,13 +91,19 @@ public function read( WP_Markdown_Native_Table_Access $access ): iterable|WP_Mar
 $unbounded_left = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT tr.object_id, tt.taxonomy FROM wp_term_relationships tr LEFT JOIN wp_term_taxonomy tt ON tr.term_taxonomy_id=tt.term_taxonomy_id' ) );
 $unqualified = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tr.object_id=41', 'object_id=41', $query ) ) );
 $unknown_alias = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 't.slug', 'x.slug', $query ) ) );
+$bound_columns = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT object_id, taxonomy, slug FROM wp_term_relationships tr JOIN wp_term_taxonomy tt ON tr.term_taxonomy_id=tt.term_taxonomy_id JOIN wp_terms t ON t.term_id=tt.term_id WHERE object_id=41' ) );
+$bound_where = $runtime->execute( new WP_Markdown_Query_Request( "SELECT object_id FROM wp_term_relationships tr, wp_term_taxonomy tt WHERE tr.term_taxonomy_id=tt.term_taxonomy_id AND taxonomy='category' AND object_id=41" ) );
+$ambiguous_column = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT term_taxonomy_id FROM wp_term_relationships tr JOIN wp_term_taxonomy tt ON tr.term_taxonomy_id=tt.term_taxonomy_id WHERE object_id=41' ) );
+$ambiguous_on = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT object_id FROM wp_term_relationships tr JOIN wp_term_taxonomy tt ON term_taxonomy_id=tt.term_taxonomy_id WHERE object_id=41' ) );
+$wrong_explicit_source = $runtime->execute( new WP_Markdown_Query_Request( str_replace( 'tt.taxonomy', 'tr.taxonomy', $query ) ) );
+$derived_binding = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT object_id, label FROM wp_term_relationships tr JOIN (SELECT term_taxonomy_id AS key_id, taxonomy AS label FROM wp_term_taxonomy) d ON key_id=tr.term_taxonomy_id WHERE object_id=41' ) );
 $limited = $runtime->execute( new WP_Markdown_Query_Request( $query . ' LIMIT 1' ) );
 $catalog_query = "SELECT wp_term_relationships.object_id FROM wp_term_relationships LEFT JOIN wp_term_taxonomy ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id) WHERE wp_term_taxonomy.taxonomy IN ('category') GROUP BY wp_term_relationships.object_id ORDER BY wp_term_relationships.object_id DESC LIMIT 0, 5";
 $catalog = $runtime->execute( new WP_Markdown_Query_Request( $catalog_query ) );
 $distinct_identity_group_query = "SELECT DISTINCT tr.object_id FROM wp_term_relationships tr JOIN wp_term_taxonomy tt ON tr.term_taxonomy_id=tt.term_taxonomy_id WHERE tt.taxonomy='category' GROUP BY tr.object_id";
 $distinct_identity_group = $runtime->execute( new WP_Markdown_Query_Request( $distinct_identity_group_query ) );
 $counted = $runtime->execute(
-	new WP_Markdown_Query_Request( 'SELECT COUNT(*) FROM wp_term_relationships LEFT JOIN wp_term_taxonomy ON term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id WHERE object_id = 41' )
+	new WP_Markdown_Query_Request( 'SELECT COUNT(*) FROM wp_term_relationships LEFT JOIN wp_term_taxonomy ON wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id WHERE object_id = 41' )
 );
 $core_term_ids_query = "SELECT DISTINCT t.term_id, tr.object_id FROM wp_terms AS t INNER JOIN wp_term_taxonomy AS tt ON t.term_id = tt.term_id INNER JOIN wp_term_relationships AS tr ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy IN ('category', 'post_tag', 'post_format') AND tr.object_id IN (41) ORDER BY t.name ASC";
 $core_term_ids_plan = ( new WP_Markdown_Native_Query_Parser() )->parse( $core_term_ids_query );
@@ -224,6 +230,11 @@ public function read( WP_Markdown_Native_Table_Access $access ): iterable|WP_Mar
 $meta_result = ( new WP_Markdown_Native_Query_Runtime( $meta_registry ) )->execute( new WP_Markdown_Query_Request( $meta_query ) );
 
 $checks = array(
+	'unqualified JOIN projections resolve against all source schemas' => $bound_columns->succeeded() && $result->corpus_result() === $bound_columns->corpus_result(),
+	'unqualified WHERE columns resolve to the unique joined owner' => $bound_where->succeeded() && array( array( 'object_id' => '41' ) ) === $bound_where->corpus_result()['rows'],
+	'ambiguous projection and ON columns fail rather than choosing the base table' => 'ambiguous_column' === ( $ambiguous_column->diagnostic()['reason'] ?? null ) && 'ambiguous_column' === ( $ambiguous_on->diagnostic()['reason'] ?? null ),
+	'an explicit wrong source is never rebound to another table' => ! $wrong_explicit_source->succeeded(),
+	'derived table aliases expose only their projected column names' => $derived_binding->succeeded() && array( 'object_id' => '41', 'label' => 'category' ) === $derived_binding->corpus_result()['rows'][0],
 	'plain column aliases preserve joined row order and source metadata' => $aliased->succeeded() && $expected_aliases === $aliased->corpus_result(),
 	'validated source index hints preserve taxonomy JOIN results' => $hinted->succeeded() && $result->corpus_result() === $hinted->corpus_result() && $joined_hint->succeeded() && $result->corpus_result() === $joined_hint->corpus_result(),
 	'unknown hinted indexes fail instead of silently executing' => ! $bad_hint->succeeded() && 'unsupported_index_hint' === ( $bad_hint->diagnostic()['reason'] ?? null ),

From 1397586db8bac6c1c839963b2ca68fc518e64376 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 17:33:28 -0400
Subject: [PATCH 49/53] fix(native): evaluate typed duplicate-key assignments

---
 ...wp-markdown-native-table-insert-parser.php | 35 +++++++++++--------
 ...ass-wp-markdown-native-table-mutations.php | 26 +++++++++++---
 ...ss-wp-markdown-native-table-statements.php |  9 ++---
 tests/smoke-native-table-upsert.php           | 19 ++++++++++
 4 files changed, 66 insertions(+), 23 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-table-insert-parser.php b/inc/native/class-wp-markdown-native-table-insert-parser.php
index 76be948..d7496e5 100644
--- a/inc/native/class-wp-markdown-native-table-insert-parser.php
+++ b/inc/native/class-wp-markdown-native-table-insert-parser.php
@@ -70,12 +70,12 @@ public function parse_rows( WP_Markdown_Query_Request $request ): array|WP_Markd
 				} while ( true );
 				$unless_exists = null;
 			}
-			$upsert_columns = null;
+			$upsert_assignments = null;
 			if ( 0 === strcasecmp( 'ON', (string) $this->current()->value() ) ) {
 				if ( $replace || $ignore_duplicate || null !== $unless_exists ) {
 					throw new WP_Markdown_Native_SQL_Parse_Error( 'unsupported_grammar', $this->current()->sql_offset(), 'mdi-native cannot combine INSERT IGNORE or INSERT SELECT FROM DUAL with ON DUPLICATE KEY UPDATE.' );
 				}
-				$upsert_columns = $this->upsert_assignments( $columns );
+				$upsert_assignments = $this->upsert_assignments();
 			}
 			$this->type( WP_Markdown_Native_SQL_Token::END );
 			$inserts = array();
@@ -87,7 +87,7 @@ public function parse_rows( WP_Markdown_Query_Request $request ): array|WP_Markd
 				if ( false === $row ) {
 					return $this->failure( 'invalid_insert_row', 'mdi-native requires one nonempty INSERT row.' );
 				}
-				$inserts[] = new WP_Markdown_Native_Table_Insert( $table, $row, $unless_exists, $ignore_duplicate, $upsert_columns, $replace );
+				$inserts[] = new WP_Markdown_Native_Table_Insert( $table, $row, $unless_exists, $ignore_duplicate, $upsert_assignments, $replace );
 			}
 			return $inserts;
 		} catch ( WP_Markdown_Native_SQL_Parse_Error $error ) {
@@ -320,31 +320,38 @@ private function identifier_list(): array {
 		return array_values( $columns );
 	}
 
-	/** @param array<int,string> $columns @return array<int,string> */
-	private function upsert_assignments( array $columns ): array {
+	/** @return array<int,array{target:string,kind:string,source:?string,value:int|string|null}> */
+	private function upsert_assignments(): array {
 		$this->word( 'ON' );
 		$this->word( 'DUPLICATE' );
 		$this->word( 'KEY' );
 		$this->word( 'UPDATE' );
 		$assignments = array();
-		$available = array_fill_keys( $columns, true );
 		do {
 			$target = $this->identifier();
 			$this->type( WP_Markdown_Native_SQL_Token::EQUALS );
-			$this->word( 'VALUES' );
-			$this->type( WP_Markdown_Native_SQL_Token::LEFT_PAREN );
-			$source = $this->identifier();
-			$this->type( WP_Markdown_Native_SQL_Token::RIGHT_PAREN );
-			if ( $target !== $source || isset( $assignments[ $target ] ) || ! isset( $available[ $target ] ) ) {
-				throw new WP_Markdown_Native_SQL_Parse_Error( 'unsupported_grammar', $this->current()->sql_offset(), 'mdi-native requires deterministic VALUES assignments for ON DUPLICATE KEY UPDATE.' );
+			$source = null;
+			$value = null;
+			if ( $this->is_word( 'VALUES' ) ) {
+				$this->word( 'VALUES' );
+				$this->type( WP_Markdown_Native_SQL_Token::LEFT_PAREN );
+				$source = $this->identifier();
+				$this->type( WP_Markdown_Native_SQL_Token::RIGHT_PAREN );
+				$kind = 'inserted';
+			} elseif ( in_array( $this->current()->type(), array( WP_Markdown_Native_SQL_Token::WORD, WP_Markdown_Native_SQL_Token::QUOTED_IDENTIFIER ), true ) ) {
+				$source = $this->identifier();
+				$kind = 'column';
+			} else {
+				$value = $this->literal();
+				$kind = 'literal';
 			}
-			$assignments[ $target ] = $target;
+			$assignments[] = array( 'target' => $target, 'kind' => $kind, 'source' => $source, 'value' => $value );
 			if ( WP_Markdown_Native_SQL_Token::COMMA !== $this->current()->type() ) {
 				break;
 			}
 			++$this->position;
 		} while ( true );
-		return array_values( $assignments );
+		return $assignments;
 	}
 
 	/** @return array<int,int|string|null> */
diff --git a/inc/native/class-wp-markdown-native-table-mutations.php b/inc/native/class-wp-markdown-native-table-mutations.php
index bacd63f..1316755 100644
--- a/inc/native/class-wp-markdown-native-table-mutations.php
+++ b/inc/native/class-wp-markdown-native-table-mutations.php
@@ -113,6 +113,11 @@ private function execute_insert( WP_Markdown_Query_Request $request, WP_Markdown
 		try {
 			$schema = $table['schema'];
 			$provider = $table['provider'];
+			foreach ( $insert->upsert_assignments() ?? array() as $assignment ) {
+				if ( ! $schema->has_column( $assignment['target'] ) || ( null !== $assignment['source'] && ! $schema->has_column( $assignment['source'] ) ) ) {
+					return $this->failure( 'unsupported_column', 'The duplicate-key assignment references an undeclared column.' );
+				}
+			}
 			if ( ! $this->supports_unique_indexes( $definition ) ) {
 				return $this->failure( 'unsupported_unique_collation', 'mdi-native cannot enforce a persisted string or prefix unique key without its exact collation.' );
 			}
@@ -130,7 +135,7 @@ private function execute_insert( WP_Markdown_Query_Request $request, WP_Markdown
 			}
 			$path = $directory . '/' . $suffix . '.json';
 			$table_index = $this->index_for( $root );
-			$index = $insert->is_replace() || null !== $insert->upsert_columns() || WP_Markdown_Native_Table_Index::supplies_identity( $insert->values(), $definition )
+			$index = $insert->is_replace() || null !== $insert->upsert_assignments() || WP_Markdown_Native_Table_Index::supplies_identity( $insert->values(), $definition )
 				? null
 				: $table_index->load( $suffix, $path );
 			if ( null !== $index ) {
@@ -202,23 +207,34 @@ private function execute_insert( WP_Markdown_Query_Request $request, WP_Markdown
 				if ( $insert->ignores_duplicate() ) {
 					return WP_Markdown_Query_Result::mutated( 0 );
 				}
-				$upsert_columns = $insert->upsert_columns();
-				if ( null === $upsert_columns ) {
+				$upsert_assignments = $insert->upsert_assignments();
+				if ( null === $upsert_assignments ) {
 					return $this->failure( 'duplicate_key', 'The INSERT row duplicates a persisted unique key.' );
 				}
 				$duplicate = $duplicates[0];
 				$updated = $rows[ $duplicate ];
-				foreach ( $upsert_columns as $column ) {
-					$updated[ $column ] = $row[ $column ];
+				foreach ( $upsert_assignments as $assignment ) {
+					// Existing-column references see earlier assignments; VALUES sees the proposed insert.
+					$updated[ $assignment['target'] ] = match ( $assignment['kind'] ) {
+						'inserted' => $row[ $assignment['source'] ],
+						'column' => $updated[ $assignment['source'] ],
+						default => $assignment['value'],
+					};
 				}
 				if ( true !== $schema->validate_row( $updated ) ) {
 					return $this->failure( 'invalid_insert_row', 'The INSERT row is outside the persisted table schema.' );
 				}
+				if ( ! $this->unique_values_enforceable( $updated, $definition ) ) {
+					return $this->failure( 'unsupported_unique_collation', 'The duplicate-key assignment requires an unsupported unique-key collation.' );
+				}
 				$others = $rows;
 				unset( $others[ $duplicate ] );
 				if ( $this->duplicate_row_offset( $updated, array_values( $others ), $definition, $schema ) !== null ) {
 					return $this->failure( 'duplicate_key', 'The INSERT row duplicates a persisted unique key.' );
 				}
+				if ( $updated === $rows[ $duplicate ] ) {
+					return WP_Markdown_Query_Result::mutated( 0 );
+				}
 				$rows[ $duplicate ] = $updated;
 				$written = $this->write( $path, array_values( $rows ) );
 				if ( $written instanceof WP_Markdown_Query_Result ) {
diff --git a/inc/native/class-wp-markdown-native-table-statements.php b/inc/native/class-wp-markdown-native-table-statements.php
index 6d14d18..217b7fd 100644
--- a/inc/native/class-wp-markdown-native-table-statements.php
+++ b/inc/native/class-wp-markdown-native-table-statements.php
@@ -9,13 +9,14 @@ final class WP_Markdown_Native_Table_Insert {
 	/**
 	 * @param array<string,int|string|null> $values
 	 * @param array<int,WP_Markdown_Native_Table_Predicate>|null $unless_exists
+	 * @param array<int,array{target:string,kind:string,source:?string,value:int|string|null}>|null $upsert_assignments
 	 */
 	public function __construct(
 		private readonly string $table,
 		private readonly array $values,
 		private readonly ?array $unless_exists = null,
 		private readonly bool $ignore_duplicate = false,
-		private readonly ?array $upsert_columns = null,
+		private readonly ?array $upsert_assignments = null,
 		private readonly bool $replace = false
 	) {}
 
@@ -37,9 +38,9 @@ public function ignores_duplicate(): bool {
 		return $this->ignore_duplicate;
 	}
 
-	/** @return array<int,string>|null */
-	public function upsert_columns(): ?array {
-		return $this->upsert_columns;
+	/** @return array<int,array{target:string,kind:string,source:?string,value:int|string|null}>|null */
+	public function upsert_assignments(): ?array {
+		return $this->upsert_assignments;
 	}
 
 	public function is_replace(): bool {
diff --git a/tests/smoke-native-table-upsert.php b/tests/smoke-native-table-upsert.php
index 7be2777..28f8a4a 100644
--- a/tests/smoke-native-table-upsert.php
+++ b/tests/smoke-native-table-upsert.php
@@ -26,8 +26,27 @@
 );
 $read = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT id, object_id, title FROM wp_yoast_indexable WHERE object_id = 7', 'wp_' ) );
 $fresh = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_yoast_indexable (object_id, title) VALUES (8, 'eight') ON DUPLICATE KEY UPDATE title = VALUES(title)", 'wp_' ) );
+$cleared = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_yoast_indexable (id, object_id, title) VALUES (1, 7, 'ignored') ON DUPLICATE KEY UPDATE title = NULL" ) );
+$cleared_row = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT title FROM wp_yoast_indexable WHERE id = 1' ) );
+$noop = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_yoast_indexable (id, object_id, title) VALUES (1, 7, 'ignored') ON DUPLICATE KEY UPDATE object_id = object_id, title = NULL" ) );
+$ordered = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_yoast_indexable (id, object_id, title) VALUES (1, 7, 'incoming') ON DUPLICATE KEY UPDATE object_id = 9, title = object_id" ) );
+$ordered_row = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT object_id, title FROM wp_yoast_indexable WHERE id = 1' ) );
+$cross_values = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_yoast_indexable (id, object_id, title) VALUES (1, 9, 'incoming') ON DUPLICATE KEY UPDATE title = VALUES(object_id)" ) );
+$bad_target = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_yoast_indexable (id, object_id, title) VALUES (3, 10, 'new') ON DUPLICATE KEY UPDATE absent_column = NULL" ) );
+$new_literal = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_yoast_indexable (id, object_id, title) VALUES (3, 10, 'new') ON DUPLICATE KEY UPDATE title = NULL" ) );
+$new_row = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT title FROM wp_yoast_indexable WHERE id = 3' ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'CREATE TABLE wp_unique_labels (id int NOT NULL, label varchar(20) NOT NULL, PRIMARY KEY(id), UNIQUE KEY label(label))' ) );
+$runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_unique_labels (id,label) VALUES (1,'original')" ) );
+$unsupported_unique = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_unique_labels (id,label) VALUES (1,'original') ON DUPLICATE KEY UPDATE label='caf\xC3\xA9'" ) );
 
 $checks = array(
+	'literal assignments preserve fail-closed unique-key enforcement' => ! $unsupported_unique->succeeded() && 'unsupported_unique_collation' === $unsupported_unique->diagnostic()['reason'],
+	'literal NULL assignments clear only a conflicting row' => 2 === $cleared->return_value() && null === $cleared_row->corpus_result()['rows'][0]['title'],
+	'unchanged duplicate assignments report zero affected rows' => 0 === $noop->return_value() && 0 === $noop->wpdb_state()['insert_id'],
+	'column references observe earlier duplicate assignments in order' => 2 === $ordered->return_value() && array( 'object_id' => '9', 'title' => '9' ) === $ordered_row->corpus_result()['rows'][0],
+	'VALUES may refer to a different inserted column' => $cross_values->succeeded() && 0 === $cross_values->return_value(),
+	'unknown duplicate target fails even on the insert branch' => ! $bad_target->succeeded() && 'unsupported_column' === $bad_target->diagnostic()['reason'],
+	'duplicate literals are not applied to a newly inserted row' => 1 === $new_literal->return_value() && 'new' === $new_row->corpus_result()['rows'][0]['title'],
 	'the first insert persists' => 1 === $insert->return_value() && 1 === $insert->wpdb_state()['insert_id'],
 	'ON DUPLICATE KEY UPDATE rewrites the conflicting row' => 2 === $upsert->return_value()
 		&& 1 === $upsert->wpdb_state()['insert_id']

From 5f02fa0b8be60af25b4cf35ecbc2b62b7aa33008 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 17:56:59 -0400
Subject: [PATCH 50/53] fix(native): apply multiple ALTER actions atomically

---
 ...ss-wp-markdown-native-schema-mutations.php | 48 +++++++++++++++++++
 tests/smoke-native-alter-table.php            | 17 +++++++
 2 files changed, 65 insertions(+)

diff --git a/inc/native/class-wp-markdown-native-schema-mutations.php b/inc/native/class-wp-markdown-native-schema-mutations.php
index abe293f..1a2b0fa 100644
--- a/inc/native/class-wp-markdown-native-schema-mutations.php
+++ b/inc/native/class-wp-markdown-native-schema-mutations.php
@@ -157,6 +157,25 @@ private function execute_alter( WP_Markdown_Query_Request $request, string $sql
 		if ( 1 !== preg_match( '/^[A-Za-z_][A-Za-z0-9_]*$/D', $suffix ) || null === $this->registry->definition( $table ) ) {
 			return $this->failure( 'unknown_table', 'mdi-native cannot alter a table it does not persist.' );
 		}
+		try {
+			$actions = array();
+			$start = 0;
+			$depth = 0;
+			foreach ( ( new WP_Markdown_Native_SQL_Tokenizer() )->tokenize( $action ) as $token ) {
+				if ( WP_Markdown_Native_SQL_Token::LEFT_PAREN === $token->type() ) { ++$depth; }
+				if ( WP_Markdown_Native_SQL_Token::RIGHT_PAREN === $token->type() ) { --$depth; }
+				if ( 0 === $depth && WP_Markdown_Native_SQL_Token::COMMA === $token->type() ) {
+					$actions[] = trim( substr( $action, $start, $token->sql_offset() - $start ) );
+					$start = $token->sql_offset() + 1;
+				}
+			}
+			$actions[] = trim( substr( $action, $start ) );
+		} catch ( WP_Markdown_Native_SQL_Parse_Error ) {
+			return $this->failure( 'unsupported_schema', 'The ALTER TABLE actions could not be parsed.' );
+		}
+		if ( count( $actions ) > 1 ) {
+			return $this->execute_alter_actions( $request, $table, $actions );
+		}
 
 		if ( 1 === preg_match( '/^ADD\s+(?:(?:UNIQUE\s+)?(?:INDEX|KEY)\s+`?[A-Za-z0-9_]+`?|PRIMARY\s+KEY)\s*\(.+\)$/is', $action ) ) {
 			return $this->execute_add_index( $table, $suffix, $action );
@@ -242,6 +261,35 @@ private function execute_alter( WP_Markdown_Query_Request $request, string $sql
 		}
 	}
 
+	/** Apply supported ALTER actions atomically after the outer DDL implicit commit. */
+	private function execute_alter_actions( WP_Markdown_Query_Request $request, string $table, array $actions ): WP_Markdown_Query_Result {
+		if ( null === $this->transactions || count( $actions ) > 64 || in_array( '', $actions, true ) ) {
+			return $this->failure( 'unsupported_schema', 'A bounded multi-action ALTER requires a transaction journal.' );
+		}
+		$locked = $this->transactions->begin_write();
+		if ( true !== $locked ) {
+			return $this->failure( 'transaction_write_lock_failed', $locked );
+		}
+		$begun = $this->transactions->begin();
+		if ( true !== $begun ) {
+			return $this->failure( 'transaction_journal_failed', $begun );
+		}
+		try {
+			foreach ( $actions as $action ) {
+				$result = $this->execute_alter( $request, 'ALTER TABLE `' . $table . '` ' . $action );
+				if ( ! $result->succeeded() ) {
+					$restored = $this->transactions->rollback();
+					return true === $restored ? $result : $this->failure( 'transaction_rollback_failed', $restored );
+				}
+			}
+			$committed = $this->transactions->commit();
+			return true === $committed ? WP_Markdown_Query_Result::schema_changed() : $this->failure( 'transaction_commit_failed', $committed );
+		} catch ( Throwable ) {
+			$restored = $this->transactions->rollback();
+			return $this->failure( 'schema_mutation_failed', true === $restored ? 'The ALTER actions failed and were restored.' : $restored );
+		}
+	}
+
 	/**
 	 * Drop one persisted table.
 	 *
diff --git a/tests/smoke-native-alter-table.php b/tests/smoke-native-alter-table.php
index 502d81d..6a055dc 100644
--- a/tests/smoke-native-alter-table.php
+++ b/tests/smoke-native-alter-table.php
@@ -109,8 +109,25 @@ function snapshot_rows( string $root ): array {
 $unsupported_action = $runtime->execute(
 	new WP_Markdown_Query_Request( 'ALTER TABLE wp_agents ENGINE = InnoDB', 'wp_' )
 );
+$combined = $runtime->execute( new WP_Markdown_Query_Request( "ALTER TABLE wp_agents ADD COLUMN owner_id bigint unsigned DEFAULT NULL, ADD KEY owner_id (owner_id), ADD COLUMN tags varchar(40) DEFAULT 'one,two'" ) );
+$combined_row = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT owner_id, tags FROM wp_agents WHERE id = 1' ) );
+$combined_index = $runtime->execute( new WP_Markdown_Query_Request( "SHOW INDEX FROM wp_agents WHERE Key_name = 'owner_id'" ) );
+$before_failed_schema = persisted_schema( $root );
+$before_failed_rows = snapshot_rows( $root );
+$failed_combined = $runtime->execute( new WP_Markdown_Query_Request( 'ALTER TABLE wp_agents ADD COLUMN transient_field int DEFAULT 7, ADD KEY invalid_key (missing_field)' ) );
+$after_failed_schema = persisted_schema( $root );
+$after_failed_rows = snapshot_rows( $root );
+$after_failed_columns = $runtime->execute( new WP_Markdown_Query_Request( 'DESCRIBE wp_agents' ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'START TRANSACTION' ) );
+$runtime->execute( new WP_Markdown_Query_Request( "UPDATE wp_agents SET label = 'committed-before-ddl' WHERE id = 1" ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'ALTER TABLE wp_agents ADD COLUMN transient_again int, ADD KEY invalid_again (missing_field)' ) );
+$runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK' ) );
+$committed_before_ddl = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT label FROM wp_agents WHERE id = 1' ) );
 
 $checks = array(
+	'multi-action ALTER adds columns and indexes in one statement' => $combined->succeeded() && array( 'owner_id' => null, 'tags' => 'one,two' ) === $combined_row->corpus_result()['rows'][0] && 1 === $combined_index->return_value(),
+	'a failed later ALTER action restores schema rows and registry' => ! $failed_combined->succeeded() && $before_failed_schema === $after_failed_schema && $before_failed_rows === $after_failed_rows && ! in_array( 'transient_field', array_column( $after_failed_columns->corpus_result()['rows'], 'Field' ), true ),
+	'failed atomic ALTER still preserves the outer implicit commit' => 'committed-before-ddl' === $committed_before_ddl->corpus_result()['rows'][0]['label'],
 	'MODIFY rewrites the persisted column definition' => true === $modified->succeeded()
 		&& str_contains( $after_modify, 'LONGTEXT NOT NULL' )
 		&& ! str_contains( $after_modify, 'instance_key VARCHAR(60) NULL' ),

From e75f32f1823d7163a1727ae7b64bf599ddf02642 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 18:11:40 -0400
Subject: [PATCH 51/53] fix(native): filter non-indexed snapshot columns

---
 inc/native/class-wp-markdown-native-query-executor.php | 7 ++++---
 tests/smoke-native-table-upsert.php                    | 3 +++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index 5f7ef1c..c4ed64e 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -459,7 +459,7 @@ private function execute_query_plan( WP_Markdown_Native_Query_Plan $plan, bool $
 		if ( array() !== $predicates
 			&& null === $pushdown
 			&& ! $table['provider'] instanceof WP_Markdown_Native_JSON_Partition_Provider
-			&& ! $this->allows_residual_scan( $predicates, $schema )
+			&& ! $this->allows_residual_scan( $predicates, $schema, $table['provider'] instanceof WP_Markdown_Native_JSON_Snapshot_Provider )
 		) {
 			return $this->failure( 'unsupported_lookup', 'mdi-native requires one indexable predicate for a filtered query.' );
 		}
@@ -1885,7 +1885,7 @@ private function derived_source( WP_Markdown_Native_Query_Plan $plan, string $na
 	}
 
 	/** @param array<int,WP_Markdown_Native_Query_Predicate> $predicates */
-	private function allows_residual_scan( array $predicates, WP_Markdown_Native_Table_Schema $schema ): bool {
+	private function allows_residual_scan( array $predicates, WP_Markdown_Native_Table_Schema $schema, bool $snapshot = false ): bool {
 		$indexed = $this->indexed_columns( $schema );
 		foreach ( $predicates as $predicate ) {
 			if ( null !== $predicate->cast() ) {
@@ -1916,7 +1916,8 @@ private function allows_residual_scan( array $predicates, WP_Markdown_Native_Tab
 			if ( in_array( $type, array( 1, 2, 3, 4, 5, 8, 9, 246 ), true ) ) {
 				continue;
 			}
-			if ( isset( $indexed[ $column ] )
+			// Snapshots already materialize rows; retain lookup validators even on scans.
+			if ( ( $snapshot || isset( $indexed[ $column ] ) )
 				&& ! $schema->is_lookup( $column )
 				&& $schema->allows_filter( $column, $predicate->operator(), $predicate->values() ) ) {
 				continue;
diff --git a/tests/smoke-native-table-upsert.php b/tests/smoke-native-table-upsert.php
index 28f8a4a..6ff776a 100644
--- a/tests/smoke-native-table-upsert.php
+++ b/tests/smoke-native-table-upsert.php
@@ -26,6 +26,8 @@
 );
 $read = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT id, object_id, title FROM wp_yoast_indexable WHERE object_id = 7', 'wp_' ) );
 $fresh = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_yoast_indexable (object_id, title) VALUES (8, 'eight') ON DUPLICATE KEY UPDATE title = VALUES(title)", 'wp_' ) );
+$unindexed_read = $runtime->execute( new WP_Markdown_Query_Request( "SELECT id FROM wp_yoast_indexable WHERE title = 'two'" ) );
+$unindexed_membership = $runtime->execute( new WP_Markdown_Query_Request( "SELECT id FROM wp_yoast_indexable WHERE title IN ('two', 'eight') ORDER BY id" ) );
 $cleared = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_yoast_indexable (id, object_id, title) VALUES (1, 7, 'ignored') ON DUPLICATE KEY UPDATE title = NULL" ) );
 $cleared_row = $runtime->execute( new WP_Markdown_Query_Request( 'SELECT title FROM wp_yoast_indexable WHERE id = 1' ) );
 $noop = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_yoast_indexable (id, object_id, title) VALUES (1, 7, 'ignored') ON DUPLICATE KEY UPDATE object_id = object_id, title = NULL" ) );
@@ -40,6 +42,7 @@
 $unsupported_unique = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_unique_labels (id,label) VALUES (1,'original') ON DUPLICATE KEY UPDATE label='caf\xC3\xA9'" ) );
 
 $checks = array(
+	'validated snapshots filter non-indexed equality and membership columns' => $unindexed_read->succeeded() && array( array( 'id' => '1' ) ) === $unindexed_read->corpus_result()['rows'] && $unindexed_membership->succeeded() && array( array( 'id' => '1' ), array( 'id' => '2' ) ) === $unindexed_membership->corpus_result()['rows'],
 	'literal assignments preserve fail-closed unique-key enforcement' => ! $unsupported_unique->succeeded() && 'unsupported_unique_collation' === $unsupported_unique->diagnostic()['reason'],
 	'literal NULL assignments clear only a conflicting row' => 2 === $cleared->return_value() && null === $cleared_row->corpus_result()['rows'][0]['title'],
 	'unchanged duplicate assignments report zero affected rows' => 0 === $noop->return_value() && 0 === $noop->wpdb_state()['insert_id'],

From 6b10e4af74f72a12e5950c3748d29dc2d889b4d0 Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 18:25:09 -0400
Subject: [PATCH 52/53] fix(native): aggregate typed numeric scalar expressions

---
 ...lass-wp-markdown-native-query-executor.php | 61 +++++++++++++++----
 .../class-wp-markdown-native-query-parser.php | 21 +++++--
 tests/smoke-native-aggregates.php             | 13 ++++
 3 files changed, 79 insertions(+), 16 deletions(-)

diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index c4ed64e..b15ff77 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -404,6 +404,25 @@ private function execute_query_plan( WP_Markdown_Native_Query_Plan $plan, bool $
 		foreach ( $scalar_projection as $scalar ) {
 			$scalar_columns = array_merge( $scalar_columns, $scalar['expression']->columns() );
 		}
+		foreach ( $plan->aggregates() as $aggregate ) {
+			if ( isset( $aggregate['expression'] ) ) {
+				$expression = $aggregate['expression'];
+				$scalar_columns = array_merge( $scalar_columns, $expression->columns() );
+				foreach ( $expression->columns() as $column ) {
+					if ( ! $schema->has_column( $column ) ) {
+						return $this->failure( 'unsupported_column', 'mdi-native cannot query the requested aggregate column.' );
+					}
+				}
+				foreach ( $expression->predicates() as $predicate ) {
+					if ( ! $schema->supports_predicate( $predicate ) ) {
+						return $this->failure( 'unsupported_lookup', 'mdi-native cannot apply the requested aggregate predicate.' );
+					}
+				}
+				if ( ! $this->is_numeric_expression( $expression, $schema ) ) {
+					return $this->failure( 'unsupported_aggregate', 'mdi-native aggregates numeric scalar expressions only.' );
+				}
+			}
+		}
 		$columns = array_merge( $projection, $scalar_columns );
 		foreach ( $scalar_predicates as $predicate ) { $columns = array_merge( $columns, $predicate->columns() ); }
 		if ( null !== $boolean_predicate ) { $columns = array_merge( $columns, $boolean_predicate->columns() ); }
@@ -676,13 +695,13 @@ private function accumulate_aggregates( array &$state, array $row, array $aggreg
 		foreach ( $aggregates as $index => $aggregate ) {
 			$current = $state[ $index ] ?? array( 'count' => 0, 'sum' => null, 'min' => null, 'max' => null, 'values' => array() );
 			$column = $aggregate['column'];
-			if ( null === $column ) {
+			if ( null === $column && ! isset( $aggregate['expression'] ) ) {
 				// COUNT(*) reports over rows, so a NULL column cannot skip one.
 				++$current['count'];
 				$state[ $index ] = $current;
 				continue;
 			}
-			$value = $row[ $column ] ?? null;
+			$value = isset( $aggregate['expression'] ) ? $this->evaluate_scalar( $aggregate['expression'], $row, $schema ) : ( $row[ $column ] ?? null );
 			if ( null === $value ) {
 				// SQL aggregates ignore NULL, and COUNT(column) counts values.
 				$state[ $index ] = $current;
@@ -695,24 +714,39 @@ private function accumulate_aggregates( array &$state, array $row, array $aggreg
 			if ( 'GROUP_CONCAT' === $aggregate['function'] ) {
 				$current['values'][] = (string) $value;
 			}
-			if ( null === $current['min'] || 0 > ( $schema->ordered_comparison( $column, $value, $current['min'] ) ?? 0 ) ) {
+			if ( null !== $column && ( null === $current['min'] || 0 > ( $schema->ordered_comparison( $column, $value, $current['min'] ) ?? 0 ) ) ) {
 				$current['min'] = $value;
 			}
-			if ( null === $current['max'] || 0 < ( $schema->ordered_comparison( $column, $value, $current['max'] ) ?? 0 ) ) {
+			if ( null !== $column && ( null === $current['max'] || 0 < ( $schema->ordered_comparison( $column, $value, $current['max'] ) ?? 0 ) ) ) {
 				$current['max'] = $value;
 			}
 			$state[ $index ] = $current;
 		}
 	}
 
-	/**
-	 * Report one row of ungrouped aggregates.
-	 *
-	 * An aggregate over no rows is NULL, except COUNT, which is zero.
-	 *
-	 * @param array<int,array<string,mixed>> $state      Running totals, by aggregate.
-	 * @param array<int,array<string,mixed>> $aggregates Declared aggregates.
-	 */
+	/** Validate numeric expression types before reading rows, including empty sets. */
+	private function is_numeric_expression( WP_Markdown_Native_Query_Scalar_Expression $expression, WP_Markdown_Native_Table_Schema $schema ): bool {
+		if ( 'literal' === $expression->kind() ) {
+			return null === $expression->literal() || is_int( $expression->literal() );
+		}
+		if ( 'column' === $expression->kind() ) {
+			return $schema->is_numeric_column( $expression->column() );
+		}
+		if ( 'CASE' === $expression->kind() ) {
+			foreach ( $expression->branches() as $branch ) {
+				if ( ! $this->is_numeric_expression( $branch['value'], $schema ) ) { return false; }
+			}
+			return null === $expression->else() || $this->is_numeric_expression( $expression->else(), $schema );
+		}
+		if ( in_array( $expression->kind(), array( 'COALESCE', 'IFNULL', 'NULLIF', 'ABS', 'ROUND', 'FLOOR', 'CEIL' ), true ) ) {
+			foreach ( $expression->arguments() as $argument ) {
+				if ( ! $this->is_numeric_expression( $argument, $schema ) ) { return false; }
+			}
+			return true;
+		}
+		return false;
+	}
+
 	private function aggregate_result( array $state, array $aggregates ): WP_Markdown_Query_Result {
 		$row = array();
 		$columns = array();
@@ -1353,6 +1387,9 @@ private function execute_join( WP_Markdown_Native_Query_Plan $plan ): WP_Markdow
 		}
 		foreach ( $plan->aggregates() as $aggregate ) {
 			if ( null === $aggregate['column'] ) {
+				if ( isset( $aggregate['expression'] ) ) {
+					return $this->failure( 'unsupported_aggregate', 'mdi-native does not yet aggregate scalar expressions across joins.' );
+				}
 				continue;
 			}
 			$aggregate_source = (string) $aggregate['source'];
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index 1a4c16a..b456d23 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -284,6 +284,7 @@ public function lower( WP_Markdown_Native_SQL_Select|WP_Markdown_Native_SQL_Foun
 					'source'   => $this->column_source( $aggregate['column'], $base_source, $bindings ),
 					'alias'    => $aggregate['alias'],
 					'distinct' => $aggregate['distinct'] ?? false,
+					'expression' => isset( $aggregate['expression'] ) ? $this->lower_scalar_expression( $aggregate['expression'], $base_source, $flat_source, $bindings ) : null,
 				),
 				$ast->aggregates()
 			),
@@ -459,6 +460,9 @@ private function referenced_columns( WP_Markdown_Native_SQL_Select $ast ): array
 			}
 		}
 		foreach ( $ast->aggregates() as $aggregate ) {
+			if ( isset( $aggregate['expression'] ) ) {
+				$columns = array_merge( $columns, $aggregate['expression']->columns() );
+			}
 			if ( null !== $aggregate['column'] ) {
 				$columns[] = $aggregate['column'];
 			}
@@ -588,7 +592,8 @@ private function select( bool $nested ): WP_Markdown_Native_SQL_Select|WP_Markdo
 		// COUNT(*) reports over rows; COUNT(column) counts values, so it is an
 		// aggregate like the others rather than the row-count shortcut.
 		$counts_rows = $this->matches_function( 'COUNT' )
-			&& WP_Markdown_Native_SQL_Token::STAR === ( $this->tokens[ $this->current + 2 ] ?? null )?->type();
+			&& WP_Markdown_Native_SQL_Token::STAR === ( $this->tokens[ $this->current + 2 ] ?? null )?->type()
+			&& 'FROM' === strtoupper( (string) ( $this->tokens[ $this->current + 4 ] ?? null )?->value() );
 		if ( ! $select_all && $counts_rows ) {
 			$count_all = true;
 			$this->identifier();
@@ -1329,7 +1334,7 @@ private function coalesce_disjunction( array $groups, int $sql_offset ): array {
 						'mdi-native supports OR only over uncast equality or LIKE alternatives.'
 					);
 				}
-				if ( ! in_array( $conjunct->operator(), array( '=', 'IN', 'IS NULL', 'LOWER =' ), true ) ) {
+				if ( ! in_array( $conjunct->operator(), array( '=', 'IN', 'IS NULL', 'LOWER =', 'LIKE' ), true ) ) {
 					throw new WP_Markdown_Native_SQL_Parse_Error(
 						'unsupported_or',
 						$sql_offset,
@@ -1344,7 +1349,7 @@ private function coalesce_disjunction( array $groups, int $sql_offset ): array {
 				continue;
 			}
 			$predicate = $group[0];
-			if ( ! in_array( $predicate->operator(), array( '=', 'IN', 'IS NULL', 'LOWER =' ), true ) ) {
+			if ( ! in_array( $predicate->operator(), array( '=', 'IN', 'IS NULL', 'LOWER =', 'LIKE' ), true ) ) {
 				throw new WP_Markdown_Native_SQL_Parse_Error(
 					'unsupported_or',
 					$sql_offset,
@@ -1372,7 +1377,7 @@ private function coalesce_disjunction( array $groups, int $sql_offset ): array {
 			return array( new WP_Markdown_Native_SQL_Predicate( $identifier, 'OR', array(), $alternatives ) );
 		}
 		foreach ( $alternatives as $alternative ) {
-			if ( 'IS NULL' === $alternative->operator() ) {
+			if ( in_array( $alternative->operator(), array( 'IS NULL', 'LIKE' ), true ) ) {
 				return array( new WP_Markdown_Native_SQL_Predicate( $identifier, 'OR', array(), $alternatives ) );
 			}
 		}
@@ -1447,6 +1452,14 @@ private function match_aggregate(): ?array {
 			$this->expect_type( WP_Markdown_Native_SQL_Token::LEFT_PAREN );
 			$argument = $this->current();
 			$distinct = $this->match_keyword( 'DISTINCT' );
+			if ( $this->matches_scalar_expression() ) {
+				if ( $distinct || ! in_array( $function, array( 'SUM', 'AVG' ), true ) ) {
+					$this->unsupported( $argument );
+				}
+				$expression = $this->scalar_value();
+				$this->expect_type( WP_Markdown_Native_SQL_Token::RIGHT_PAREN );
+				return array( 'function' => $function, 'column' => null, 'expression' => $expression, 'alias' => $this->scalar_alias(), 'distinct' => false );
+			}
 			$column = $this->match_type( WP_Markdown_Native_SQL_Token::STAR ) ? null : $this->identifier();
 			if ( $distinct && ( 'COUNT' !== $function || null === $column ) ) {
 				$this->unsupported( $argument );
diff --git a/tests/smoke-native-aggregates.php b/tests/smoke-native-aggregates.php
index edb4406..3c0a3df 100644
--- a/tests/smoke-native-aggregates.php
+++ b/tests/smoke-native-aggregates.php
@@ -35,6 +35,14 @@ function mdi_aggregate_row( WP_Markdown_Native_Query_Runtime $runtime, string $s
 }
 
 $totals = mdi_aggregate_row( $runtime, 'SELECT SUM(score) AS total, AVG(score) AS mean, MIN(score) AS lowest, MAX(score) AS highest FROM wp_items' );
+$conditional_sql = "SELECT COUNT(*) AS total, SUM(CASE WHEN kind = 'a' THEN 1 ELSE 0 END) AS completed, SUM(CASE WHEN kind LIKE 'b%' OR kind = 'c' THEN 1 ELSE 0 END) AS skipped FROM wp_items";
+$conditional = mdi_aggregate_row( $runtime, $conditional_sql );
+$conditional_empty = mdi_aggregate_row( $runtime, $conditional_sql . " WHERE kind = 'missing'" );
+$numeric_scalar = mdi_aggregate_row( $runtime, 'SELECT SUM(COALESCE(score, 0)) AS total, AVG(ABS(score)) AS mean FROM wp_items' );
+$scalar_null = mdi_aggregate_row( $runtime, "SELECT SUM(ABS(score)) AS total FROM wp_items WHERE kind = 'c'" );
+$bad_scalar = mdi_aggregate_row( $runtime, 'SELECT SUM(ABS(missing)) AS total FROM wp_items' );
+$bad_type = mdi_aggregate_row( $runtime, "SELECT SUM(COALESCE(kind, 'bad')) AS total FROM wp_items WHERE id = 999" );
+$conditional_groups = $runtime->execute( new WP_Markdown_Query_Request( "SELECT kind, COUNT(*) AS total, SUM(CASE WHEN score > 15 THEN 1 ELSE 0 END) AS high FROM wp_items GROUP BY kind ORDER BY kind" ) );
 $counts = mdi_aggregate_row( $runtime, 'SELECT COUNT(score) AS scored FROM wp_items' );
 $all_rows = mdi_aggregate_row( $runtime, 'SELECT COUNT(*) FROM wp_items' );
 $filtered = mdi_aggregate_row( $runtime, "SELECT SUM(score) AS total FROM wp_items WHERE kind = 'a'" );
@@ -53,6 +61,11 @@ function mdi_aggregate_row( WP_Markdown_Native_Query_Runtime $runtime, string $s
 usort( $joined_rows, static fn( array $left, array $right ): int => (int) $left['score'] <=> (int) $right['score'] );
 
 $checks = array(
+	'aliased row counts compose with conditional aggregates' => array( 'total' => '4', 'completed' => '2', 'skipped' => '2' ) === $conditional,
+	'conditional aggregates retain empty-set NULL and count semantics' => array( 'total' => '0', 'completed' => null, 'skipped' => null ) === $conditional_empty,
+	'numeric scalar aggregates reuse row-local evaluation' => array( 'total' => '60', 'mean' => '20' ) === $numeric_scalar && array( 'total' => null ) === $scalar_null,
+	'aggregate expressions validate columns and types even on empty sets' => 'unsupported_column' === ( $bad_scalar['unsupported'] ?? null ) && 'unsupported_aggregate' === ( $bad_type['unsupported'] ?? null ),
+	'conditional aggregates execute independently per group' => $conditional_groups->succeeded() && array( array( 'kind' => 'a', 'total' => '2', 'high' => '1' ), array( 'kind' => 'b', 'total' => '1', 'high' => '1' ), array( 'kind' => 'c', 'total' => '1', 'high' => '0' ) ) === $conditional_groups->corpus_result()['rows'],
 	'multiple explicit grouping columns preserve every projected value' => $grouped->succeeded() && array(
 		array( 'kind' => 'c', 'score' => null, 'n' => '1' ),
 		array( 'kind' => 'a', 'score' => '10', 'n' => '1' ),

From 8f50078ee339f1a82e369e6b4a05efb744a730dd Mon Sep 17 00:00:00 2001
From: Chris Huber <chris.huber@automattic.com>
Date: Thu, 10 Sep 2026 18:55:15 -0400
Subject: [PATCH 53/53] fix(native): evaluate scalar updates with nested
 predicates

---
 ...lass-wp-markdown-native-post-mutations.php |  8 ++-
 ...lass-wp-markdown-native-query-executor.php |  9 ++-
 .../class-wp-markdown-native-query-parser.php |  4 +-
 ...class-wp-markdown-native-query-runtime.php |  1 +
 ...ss-wp-markdown-native-scalar-evaluator.php | 60 +++++++++++++++++++
 ...wp-markdown-native-table-insert-parser.php | 57 ++++++++++++++----
 ...ass-wp-markdown-native-table-mutations.php | 43 ++++++++++---
 ...ss-wp-markdown-native-table-statements.php | 13 ++--
 tests/smoke-native-table-write.php            | 32 ++++++++++
 9 files changed, 198 insertions(+), 29 deletions(-)
 create mode 100644 inc/native/class-wp-markdown-native-scalar-evaluator.php

diff --git a/inc/native/class-wp-markdown-native-post-mutations.php b/inc/native/class-wp-markdown-native-post-mutations.php
index b7b72bc..18f7da7 100644
--- a/inc/native/class-wp-markdown-native-post-mutations.php
+++ b/inc/native/class-wp-markdown-native-post-mutations.php
@@ -75,6 +75,9 @@ private function write( WP_Markdown_Query_Request $request ): WP_Markdown_Query_
 			return $write;
 		}
 		foreach ( $write->predicates() as $predicate ) {
+			if ( $predicate instanceof WP_Markdown_Native_Table_Predicate_Group ) {
+				return $this->failure( 'unsupported_predicate', 'mdi-native post mutations require simple conjunctive restrictions.' );
+			}
 			if ( $predicate instanceof WP_Markdown_Native_Table_Subquery_Predicate ) {
 				return $this->failure( 'unsupported_subquery_shape', 'mdi-native post mutations do not support IN subqueries.' );
 			}
@@ -89,7 +92,10 @@ private function write( WP_Markdown_Query_Request $request ): WP_Markdown_Query_
 				return $this->failure( 'unsupported_mutation_column', 'The WHERE restriction names a column outside the wp_posts schema.' );
 			}
 		}
-		foreach ( array_keys( $write->values() ) as $column ) {
+		foreach ( $write->values() as $column => $value ) {
+			if ( $value instanceof WP_Markdown_Native_Query_Scalar_Expression ) {
+				return $this->failure( 'unsupported_assignment', 'mdi-native post mutations do not yet evaluate scalar assignments.' );
+			}
 			if ( ! $schema->has_column( (string) $column ) ) {
 				return $this->failure( 'unsupported_mutation_column', 'The assignment names a column outside the wp_posts schema.' );
 			}
diff --git a/inc/native/class-wp-markdown-native-query-executor.php b/inc/native/class-wp-markdown-native-query-executor.php
index b15ff77..48afb02 100644
--- a/inc/native/class-wp-markdown-native-query-executor.php
+++ b/inc/native/class-wp-markdown-native-query-executor.php
@@ -2203,7 +2203,11 @@ private function interleave_scalar_projection( array $regular, array $scalar_pro
 	}
 
 	/** Evaluate a lowered row-local scalar expression after filtering. */
-	private function evaluate_scalar( WP_Markdown_Native_Query_Scalar_Expression $expression, array $row, WP_Markdown_Native_Table_Schema $schema ): int|string|null {
+	public function evaluate_scalar( WP_Markdown_Native_Query_Scalar_Expression $expression, array $row, WP_Markdown_Native_Table_Schema $schema ): int|string|null {
+		$this->statement_now ??= gmdate( 'Y-m-d H:i:s' );
+		if ( WP_Markdown_Native_Scalar_Evaluator::supports( $expression ) ) {
+			return WP_Markdown_Native_Scalar_Evaluator::evaluate( $expression, $row );
+		}
 		$values = array_map(
 			fn( WP_Markdown_Native_Query_Scalar_Expression $argument ): int|string|null => $this->evaluate_scalar( $argument, $row, $schema ),
 			$expression->arguments()
@@ -2285,6 +2289,9 @@ private function evaluate_scalar( WP_Markdown_Native_Query_Scalar_Expression $ex
 
 	private function scalar_number( int|float|string|null $value ): int|string|null|float {
 		if ( null === $value ) { return null; }
+		if ( is_int( $value ) || ( is_string( $value ) && (string) (int) $value === $value ) ) {
+			return (int) $value;
+		}
 		$number = (float) $value;
 		return floor( $number ) === $number ? (int) $number : (string) $number;
 	}
diff --git a/inc/native/class-wp-markdown-native-query-parser.php b/inc/native/class-wp-markdown-native-query-parser.php
index b456d23..88dc6a7 100644
--- a/inc/native/class-wp-markdown-native-query-parser.php
+++ b/inc/native/class-wp-markdown-native-query-parser.php
@@ -394,7 +394,7 @@ private function lower_predicate( WP_Markdown_Native_SQL_Predicate $predicate, ?
 		);
 	}
 
-	private function lower_scalar_expression( WP_Markdown_Native_SQL_Scalar_Expression $expression, ?string $base_source, ?string $flat_source = null, array $bindings = array() ): WP_Markdown_Native_Query_Scalar_Expression {
+	public function lower_scalar_expression( WP_Markdown_Native_SQL_Scalar_Expression $expression, ?string $base_source, ?string $flat_source = null, array $bindings = array() ): WP_Markdown_Native_Query_Scalar_Expression {
 		$source = $this->column_source( $expression->identifier(), $base_source, $bindings );
 		return new WP_Markdown_Native_Query_Scalar_Expression(
 			$expression->kind(),
@@ -1061,7 +1061,7 @@ private function scalar_expression(): WP_Markdown_Native_SQL_Scalar_Expression {
 		return new WP_Markdown_Native_SQL_Scalar_Expression( $function, null, null, $arguments );
 	}
 
-	private function scalar_value(): WP_Markdown_Native_SQL_Scalar_Expression {
+	public function scalar_value(): WP_Markdown_Native_SQL_Scalar_Expression {
 		$value = $this->scalar_term();
 		while ( in_array( $this->current()->type(), array( WP_Markdown_Native_SQL_Token::PLUS, WP_Markdown_Native_SQL_Token::MINUS ), true ) ) {
 			$operator = $this->current()->type(); ++$this->current;
diff --git a/inc/native/class-wp-markdown-native-query-runtime.php b/inc/native/class-wp-markdown-native-query-runtime.php
index d92b994..b005409 100644
--- a/inc/native/class-wp-markdown-native-query-runtime.php
+++ b/inc/native/class-wp-markdown-native-query-runtime.php
@@ -7,6 +7,7 @@
 
 require_once __DIR__ . '/../class-wp-markdown-canonical-option-path.php';
 require_once __DIR__ . '/class-wp-markdown-native-query-contracts.php';
+require_once __DIR__ . '/class-wp-markdown-native-scalar-evaluator.php';
 require_once __DIR__ . '/class-wp-markdown-native-sql-session.php';
 require_once __DIR__ . '/class-wp-markdown-native-query-schema.php';
 require_once __DIR__ . '/class-wp-markdown-native-schema-catalog.php';
diff --git a/inc/native/class-wp-markdown-native-scalar-evaluator.php b/inc/native/class-wp-markdown-native-scalar-evaluator.php
new file mode 100644
index 0000000..7cd8fa5
--- /dev/null
+++ b/inc/native/class-wp-markdown-native-scalar-evaluator.php
@@ -0,0 +1,60 @@
+<?php
+/** Shared evaluator for bounded row-local scalar expressions. */
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+final class WP_Markdown_Native_Scalar_Evaluator {
+	public static function supports( WP_Markdown_Native_Query_Scalar_Expression $expression ): bool {
+		if ( ! in_array( $expression->kind(), array( 'literal', 'column', 'COALESCE', 'ADD', 'SUBTRACT', 'MULTIPLY', 'DIVIDE' ), true ) ) {
+			return false;
+		}
+		foreach ( $expression->arguments() as $argument ) {
+			if ( ! self::supports( $argument ) ) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	/** @param array<string,mixed> $row */
+	public static function evaluate( WP_Markdown_Native_Query_Scalar_Expression $expression, array $row ): int|string|null {
+		if ( ! self::supports( $expression ) ) {
+			throw new LogicException( 'Unsupported shared scalar expression.' );
+		}
+		$values = array_map( static fn( WP_Markdown_Native_Query_Scalar_Expression $argument ): int|string|null => self::evaluate( $argument, $row ), $expression->arguments() );
+		return match ( $expression->kind() ) {
+			'literal' => $expression->literal(),
+			'column' => null === $expression->source()
+				? ( $row[ (string) $expression->column() ] ?? null )
+				: ( $row[ $expression->source() ][ (string) $expression->column() ] ?? null ),
+			'COALESCE' => self::first_non_null( $values ),
+			'ADD' => in_array( null, $values, true ) ? null : self::number( self::number( $values[0] ) + self::number( $values[1] ) ),
+			'SUBTRACT' => in_array( null, $values, true ) ? null : self::number( self::number( $values[0] ) - self::number( $values[1] ) ),
+			'MULTIPLY' => in_array( null, $values, true ) ? null : self::number( self::number( $values[0] ) * self::number( $values[1] ) ),
+			'DIVIDE' => in_array( null, $values, true ) || 0.0 === (float) self::number( $values[1] ) ? null : self::number( self::number( $values[0] ) / self::number( $values[1] ) ),
+		};
+	}
+
+	/** @param array<int,int|string|null> $values */
+	private static function first_non_null( array $values ): int|string|null {
+		foreach ( $values as $value ) {
+			if ( null !== $value ) {
+				return $value;
+			}
+		}
+		return null;
+	}
+
+	private static function number( int|float|string|null $value ): int|string|null|float {
+		if ( null === $value ) {
+			return null;
+		}
+		if ( is_int( $value ) || ( is_string( $value ) && (string) (int) $value === $value ) ) {
+			return (int) $value;
+		}
+		$number = (float) $value;
+		return floor( $number ) === $number ? (int) $number : (string) $number;
+	}
+}
diff --git a/inc/native/class-wp-markdown-native-table-insert-parser.php b/inc/native/class-wp-markdown-native-table-insert-parser.php
index d7496e5..2451c3c 100644
--- a/inc/native/class-wp-markdown-native-table-insert-parser.php
+++ b/inc/native/class-wp-markdown-native-table-insert-parser.php
@@ -125,7 +125,7 @@ public function parse_write( WP_Markdown_Query_Request $request ): WP_Markdown_N
 				$this->word( 'UPDATE' );
 				$table = $this->identifier();
 				$this->word( 'SET' );
-				$values = $this->assignments();
+				$values = $this->assignments( $table );
 			}
 			$predicates = $this->where_predicates();
 			$this->type( WP_Markdown_Native_SQL_Token::END );
@@ -142,13 +142,26 @@ public function parse_write( WP_Markdown_Query_Request $request ): WP_Markdown_N
 		}
 	}
 
-	/** @return array<string,int|string|null> */
-	private function assignments(): array {
+	/** @return array<string,int|string|null|WP_Markdown_Native_Query_Scalar_Expression> */
+	private function assignments( string $table ): array {
 		$values = array();
 		do {
 			$column = $this->identifier();
+			if ( array_key_exists( $column, $values ) ) {
+				throw new WP_Markdown_Native_SQL_Parse_Error( 'duplicate_mutation_column', $this->current()->sql_offset(), 'Repeated UPDATE targets are not supported.' );
+			}
 			$this->type( WP_Markdown_Native_SQL_Token::EQUALS );
-			$values[ $column ] = $this->literal();
+			$parser = new WP_Markdown_Native_Select_AST_Parser( $this->tokens, $this->position );
+			$expression = $parser->scalar_value();
+			$this->position = $parser->position();
+			foreach ( $expression->columns() as $source ) {
+				if ( null !== $source->qualifier() && 0 !== strcasecmp( $table, $source->qualifier() ) ) {
+					throw new WP_Markdown_Native_SQL_Parse_Error( 'unsupported_mutation_column', $source->sql_offset(), 'An UPDATE expression must reference its target table.' );
+				}
+			}
+			$values[ $column ] = 'literal' === $expression->kind()
+				? ( null === $expression->literal() ? null : (string) $expression->literal() )
+				: ( new WP_Markdown_Native_Query_Parser() )->lower_scalar_expression( $expression, null, $table );
 			if ( WP_Markdown_Native_SQL_Token::COMMA !== $this->current()->type() ) {
 				break;
 			}
@@ -177,27 +190,25 @@ private function where_predicates(): array {
 		}
 		$this->word( 'WHERE' );
 
-		$predicates = array( $this->where_disjunction() );
-		while ( $this->is_word( 'AND' ) ) {
-			++$this->position;
-			$predicates[] = $this->where_disjunction();
-		}
-		return array_filter( $predicates );
+		$predicate = $this->where_disjunction();
+		return $predicate instanceof WP_Markdown_Native_Table_Predicate_Group && $predicate->all()
+			? $predicate->any()
+			: array( $predicate );
 	}
 
 	/** @return WP_Markdown_Native_Table_Predicate|WP_Markdown_Native_Table_Predicate_Group|WP_Markdown_Native_Table_Subquery_Predicate|null */
 	private function where_disjunction() {
-		$alternatives = array( $this->where_factor() );
+		$alternatives = array( $this->where_conjunction() );
 		while ( $this->is_word( 'OR' ) ) {
 			++$this->position;
-			$alternatives[] = $this->where_factor();
+			$alternatives[] = $this->where_conjunction();
 		}
 		$alternatives = array_values( array_filter( $alternatives ) );
 		if ( array() === $alternatives ) {
 			return null;
 		}
 		foreach ( $alternatives as $alternative ) {
-			if ( $alternative instanceof WP_Markdown_Native_Table_Subquery_Predicate && 1 !== count( $alternatives ) ) {
+			if ( 1 !== count( $alternatives ) && $this->has_subquery( $alternative ) ) {
 				throw new WP_Markdown_Native_SQL_Parse_Error( 'unsupported_subquery_shape', $this->current()->sql_offset(), 'mdi-native supports IN subqueries only as conjunctive write restrictions.' );
 			}
 		}
@@ -206,6 +217,26 @@ private function where_disjunction() {
 			: new WP_Markdown_Native_Table_Predicate_Group( $alternatives );
 	}
 
+	/** @return WP_Markdown_Native_Table_Predicate|WP_Markdown_Native_Table_Predicate_Group|WP_Markdown_Native_Table_Subquery_Predicate|null */
+	private function where_conjunction() {
+		$terms = array( $this->where_factor() );
+		while ( $this->is_word( 'AND' ) ) {
+			++$this->position;
+			$terms[] = $this->where_factor();
+		}
+		return 1 === count( $terms ) ? $terms[0] : new WP_Markdown_Native_Table_Predicate_Group( $terms, true );
+	}
+
+	private function has_subquery( mixed $predicate ): bool {
+		if ( $predicate instanceof WP_Markdown_Native_Table_Subquery_Predicate ) { return true; }
+		if ( $predicate instanceof WP_Markdown_Native_Table_Predicate_Group ) {
+			foreach ( $predicate->any() as $term ) {
+				if ( $this->has_subquery( $term ) ) { return true; }
+			}
+		}
+		return false;
+	}
+
 	/** @return WP_Markdown_Native_Table_Predicate|WP_Markdown_Native_Table_Predicate_Group|WP_Markdown_Native_Table_Subquery_Predicate|null */
 	private function where_factor() {
 		if ( WP_Markdown_Native_SQL_Token::LEFT_PAREN === $this->current()->type() ) {
diff --git a/inc/native/class-wp-markdown-native-table-mutations.php b/inc/native/class-wp-markdown-native-table-mutations.php
index 1316755..ccc48a2 100644
--- a/inc/native/class-wp-markdown-native-table-mutations.php
+++ b/inc/native/class-wp-markdown-native-table-mutations.php
@@ -532,11 +532,24 @@ private function execute_write( WP_Markdown_Query_Request $request ): WP_Markdow
 				}
 			}
 		}
-		foreach ( array_keys( $write->values() ) as $column ) {
+		foreach ( $write->values() as $column => $value ) {
 			if ( ! $schema->has_column( (string) $column ) ) {
 				return $this->failure( 'unsupported_mutation_column', 'The assignment names a column outside the persisted table schema.' );
 			}
+			if ( $value instanceof WP_Markdown_Native_Query_Scalar_Expression ) {
+				foreach ( $value->columns() as $source ) {
+					if ( ! $schema->has_column( $source ) ) {
+						return $this->failure( 'unsupported_mutation_column', 'The expression names a column outside the persisted table schema.' );
+					}
+				}
+				foreach ( $value->predicates() as $predicate ) {
+					if ( ! $schema->supports_predicate( $predicate ) ) {
+						return $this->failure( 'unsupported_predicate', 'The assignment expression uses an unsupported predicate.' );
+					}
+				}
+			}
 		}
+		$scalar_runtime = new WP_Markdown_Native_Query_Runtime( $this->registry, new WP_Markdown_Native_Query_Parser() );
 		$root = $this->root_for( $write->table() );
 		$directory = $this->tables_directory( $root );
 		if ( $directory instanceof WP_Markdown_Query_Result ) {
@@ -574,7 +587,13 @@ private function execute_write( WP_Markdown_Query_Request $request ): WP_Markdow
 				if ( ! $write->is_update() ) {
 					continue;
 				}
-				$updated = array_merge( $row, $write->values() );
+				$updated = $row;
+				foreach ( $write->values() as $column => $value ) {
+					$value = $value instanceof WP_Markdown_Native_Query_Scalar_Expression
+						? $scalar_runtime->evaluate_scalar( $value, $updated, $schema )
+						: $value;
+					$updated[ $column ] = null === $value ? null : (string) $value;
+				}
 				if ( true !== $schema->validate_row( $updated ) ) {
 					return $this->failure( 'invalid_update_row', 'The UPDATE row is outside the persisted table schema.' );
 				}
@@ -628,6 +647,12 @@ private function resolve_subquery_predicates( array $predicates, WP_Markdown_Nat
 		$query_parser = new WP_Markdown_Native_Query_Parser();
 		$query_runtime = new WP_Markdown_Native_Query_Runtime( $this->registry, $query_parser );
 		foreach ( $predicates as $predicate ) {
+			if ( $predicate instanceof WP_Markdown_Native_Table_Predicate_Group ) {
+				$terms = $this->resolve_subquery_predicates( $predicate->any(), $schema, $target_table );
+				if ( $terms instanceof WP_Markdown_Query_Result ) { return $terms; }
+				$resolved[] = new WP_Markdown_Native_Table_Predicate_Group( $terms, $predicate->all() );
+				continue;
+			}
 			if ( ! $predicate instanceof WP_Markdown_Native_Table_Subquery_Predicate ) {
 				$resolved[] = $predicate;
 				continue;
@@ -698,11 +723,12 @@ private function index_excludes( array $index, array $predicates ): bool {
 	private function index_predicate_excludes( array $index, mixed $predicate ): bool {
 		if ( $predicate instanceof WP_Markdown_Native_Table_Predicate_Group ) {
 			foreach ( $predicate->any() as $alternative ) {
-				if ( ! $this->index_predicate_excludes( $index, $alternative ) ) {
-					return false;
+				$excluded = $this->index_predicate_excludes( $index, $alternative );
+				if ( $excluded === $predicate->all() ) {
+					return $excluded;
 				}
 			}
-			return true;
+			return ! $predicate->all();
 		}
 		if ( ! $predicate instanceof WP_Markdown_Native_Table_Predicate || '=' !== $predicate->operator() ) {
 			return false;
@@ -743,11 +769,12 @@ private function restricts( array $row, array $predicates, WP_Markdown_Native_Ta
 	private function restricts_predicate( array $row, $predicate, WP_Markdown_Native_Table_Schema $schema ): bool {
 		if ( $predicate instanceof WP_Markdown_Native_Table_Predicate_Group ) {
 			foreach ( $predicate->any() as $alternative ) {
-				if ( $this->restricts_predicate( $row, $alternative, $schema ) ) {
-					return true;
+				$matches = $this->restricts_predicate( $row, $alternative, $schema );
+				if ( $matches !== $predicate->all() ) {
+					return $matches;
 				}
 			}
-			return array() === $predicate->any();
+			return $predicate->all();
 		}
 		$value = $row[ $predicate->column() ] ?? null;
 		if ( $predicate->matches_null() && null === $value ) {
diff --git a/inc/native/class-wp-markdown-native-table-statements.php b/inc/native/class-wp-markdown-native-table-statements.php
index 217b7fd..fdc7e43 100644
--- a/inc/native/class-wp-markdown-native-table-statements.php
+++ b/inc/native/class-wp-markdown-native-table-statements.php
@@ -82,18 +82,23 @@ public function operator(): string {
 	}
 }
 
-/** One OR group of restrictions, evaluated as a disjunction per row. */
+/** A nested group of restrictions, using AND when all is true and OR otherwise. */
 final class WP_Markdown_Native_Table_Predicate_Group {
 
 	/** @param array<int,WP_Markdown_Native_Table_Predicate|self> $any */
 	public function __construct(
-		private readonly array $any
+		private readonly array $any,
+		private readonly bool $all = false
 	) {}
 
 	/** @return array<int,WP_Markdown_Native_Table_Predicate|self> */
 	public function any(): array {
 		return $this->any;
 	}
+
+	public function all(): bool {
+		return $this->all;
+	}
 }
 
 /** A typed single-column IN predicate whose members come from a typed SELECT. */
@@ -116,7 +121,7 @@ public function query(): WP_Markdown_Native_SQL_Select {
 final class WP_Markdown_Native_Table_Write {
 
 	/**
-	 * @param array<string,int|string|null>              $values     Assignments for an UPDATE.
+	 * @param array<string,int|string|null|WP_Markdown_Native_Query_Scalar_Expression> $values Assignments for an UPDATE, in evaluation order.
 	 * @param array<int,WP_Markdown_Native_Table_Predicate|WP_Markdown_Native_Table_Predicate_Group|WP_Markdown_Native_Table_Subquery_Predicate> $predicates Conjunctive restrictions.
 	 */
 	public function __construct(
@@ -134,7 +139,7 @@ public function table(): string {
 		return $this->table;
 	}
 
-	/** @return array<string,int|string|null> */
+	/** @return array<string,int|string|null|WP_Markdown_Native_Query_Scalar_Expression> */
 	public function values(): array {
 		return $this->values;
 	}
diff --git a/tests/smoke-native-table-write.php b/tests/smoke-native-table-write.php
index fc69754..614ab6e 100644
--- a/tests/smoke-native-table-write.php
+++ b/tests/smoke-native-table-write.php
@@ -266,7 +266,39 @@ function column_values( string $root, string $column, string $table = 'agents' )
 $runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK', 'wp_' ) );
 $after_rollback = column_values( $root, 'label' );
 
+$runtime->execute( new WP_Markdown_Query_Request( 'CREATE TABLE wp_claims (id bigint NOT NULL, generation bigint NULL, mirror bigint NULL, state varchar(20) NOT NULL, claimed_at datetime NULL, label varchar(10) NOT NULL, PRIMARY KEY (id))' ) );
+$claim_fixture = $runtime->execute( new WP_Markdown_Query_Request( "INSERT INTO wp_claims (id, generation, mirror, state, claimed_at, label) VALUES (1,NULL,NULL,'preparing',NULL,'one'),(2,2,NULL,'enqueuing','2026-09-10 23:00:00','1234567890'),(3,2,NULL,'enqueuing','2026-09-10 20:00:00','three'),(4,9,NULL,'enqueuing','2026-09-10 20:00:00','four')" ) );
+if ( ! $claim_fixture->succeeded() ) { throw new RuntimeException( json_encode( $claim_fixture->diagnostic() ) ); }
+$claim_sql = "UPDATE wp_claims SET generation = COALESCE(generation, 0) + 1, mirror = generation, state = 'enqueuing', claimed_at = '2026-09-10 23:00:00' WHERE id < 4 AND (state IN ('preparing', 'enqueue_failed') OR (state = 'enqueuing' AND (claimed_at IS NULL OR claimed_at < '2026-09-10 22:00:00')))";
+$claimed = $runtime->execute( new WP_Markdown_Query_Request( $claim_sql ) );
+$claim_rows = table_rows( $root, 'claims' );
+$claim_replay = $runtime->execute( new WP_Markdown_Query_Request( $claim_sql ) );
+$bad_expression = $runtime->execute( new WP_Markdown_Query_Request( 'UPDATE wp_claims SET generation = COALESCE(missing, 0) + 1 WHERE id = 999' ) );
+$wrong_source = $runtime->execute( new WP_Markdown_Query_Request( 'UPDATE wp_claims SET generation = other.generation WHERE id = 999' ) );
+$repeated_target = $runtime->execute( new WP_Markdown_Query_Request( 'UPDATE wp_claims SET generation = 1, generation = generation + 1' ) );
+$late_failure = $runtime->execute( new WP_Markdown_Query_Request( "UPDATE wp_claims SET label = CONCAT(label, '!') WHERE id IN (1, 2)" ) );
+$after_late_failure = table_rows( $root, 'claims' );
+$unique_failure = $runtime->execute( new WP_Markdown_Query_Request( 'UPDATE wp_claims SET id = COALESCE(mirror, 1) WHERE id IN (1, 2)' ) );
+$after_unique_failure = table_rows( $root, 'claims' );
+$runtime->execute( new WP_Markdown_Query_Request( 'BEGIN' ) );
+$precedence = $runtime->execute( new WP_Markdown_Query_Request( "UPDATE wp_claims SET generation = generation + 10 WHERE id = 1 OR id = 3 AND state = 'never'" ) );
+$precedence_rows = table_rows( $root, 'claims' );
+$nested_delete = $runtime->execute( new WP_Markdown_Query_Request( "DELETE FROM wp_claims WHERE (id = 1 OR id = 3) AND state = 'enqueuing'" ) );
+$runtime->execute( new WP_Markdown_Query_Request( "UPDATE wp_claims SET generation = '9007199254740993' WHERE id = 4" ) );
+$large_increment = $runtime->execute( new WP_Markdown_Query_Request( 'UPDATE wp_claims SET generation = generation + 1 WHERE id = 4' ) );
+$large_rows = table_rows( $root, 'claims' );
+$runtime->execute( new WP_Markdown_Query_Request( 'ROLLBACK' ) );
+$restored_claims = table_rows( $root, 'claims' );
+
 $checks = array(
+	'nested lease predicates claim only eligible rows and assignments observe earlier values' => 2 === $claimed->return_value() && array( '1', '2', '3', '9' ) === array_column( $claim_rows, 'generation' ) && array( '1', null, '3', null ) === array_column( $claim_rows, 'mirror' ),
+	'a repeated claim cannot take an active lease' => 0 === $claim_replay->return_value(),
+	'unknown sources and repeated targets fail before mutation even without matching rows' => ! $bad_expression->succeeded() && ! $wrong_source->succeeded() && ! $repeated_target->succeeded(),
+	'a later invalid row prevents every scalar UPDATE write' => ! $late_failure->succeeded() && $claim_rows === $after_late_failure,
+	'scalar assignments preserve unique-key enforcement atomically' => ! $unique_failure->succeeded() && $claim_rows === $after_unique_failure,
+	'AND binds tighter than OR in write predicates' => 1 === $precedence->return_value() && array( '11', '2', '3', '9' ) === array_column( $precedence_rows, 'generation' ),
+	'rollback restores scalar updates and grouped deletes' => 2 === $nested_delete->return_value() && $claim_rows === $restored_claims,
+	'integer arithmetic preserves values beyond floating-point precision' => 1 === $large_increment->return_value() && '9007199254740994' === $large_rows[1]['generation'],
 	'the fixture table is created' => 0 === $created->return_value() || true === $created->succeeded(),
 	'a disjunctive NULL restriction updates every matching row' => 2 === $backfill->return_value()
 		&& array( 'default', 'default', 'keep' ) === $after_backfill,