Add support for UNLOGGED tables

internal/diff/diff.go

@@ -24,6 +24,7 @@ const (
 	DiffTypeTableComment
 	DiffTypeTableColumnComment
 	DiffTypeTableIndexComment
+	DiffTypeTablePersistence
 	DiffTypeView
 	DiffTypeViewTrigger
 	DiffTypeViewComment
@@ -66,6 +67,8 @@ func (d DiffType) String() string {
 		return "table.column.comment"
 	case DiffTypeTableIndexComment:
 		return "table.index.comment"
+	case DiffTypeTablePersistence:
+		return "table.persistence"
 	case DiffTypeView:
 		return "view"
 	case DiffTypeViewTrigger:
@@ -138,6 +141,8 @@ func (d *DiffType) UnmarshalJSON(data []byte) error {
 		*d = DiffTypeTableColumnComment
 	case "table.index.comment":
 		*d = DiffTypeTableIndexComment
+	case "table.persistence":
+		*d = DiffTypeTablePersistence
 	case "view":
 		*d = DiffTypeView
 	case "view.trigger":
@@ -386,6 +391,7 @@ type tableDiff struct {
 	CommentChanged      bool
 	OldComment          string
 	NewComment          string
+	PersistenceChanged  bool
 }
 
 // ColumnDiff represents changes to a column

internal/diff/table.go

@@ -328,6 +328,11 @@ func diffTables(oldTable, newTable *ir.Table, targetSchema string) *tableDiff {
 		diff.NewComment = newTable.Comment
 	}
 
+	// Check for persistence (UNLOGGED/LOGGED) changes
+	if oldTable.Unlogged != newTable.Unlogged {
+		diff.PersistenceChanged = true
+	}
+
 	// Return nil if no changes
 	if len(diff.AddedColumns) == 0 && len(diff.DroppedColumns) == 0 &&
 		len(diff.ModifiedColumns) == 0 && len(diff.AddedConstraints) == 0 &&
@@ -337,7 +342,7 @@ func diffTables(oldTable, newTable *ir.Table, targetSchema string) *tableDiff {
 		len(diff.DroppedTriggers) == 0 && len(diff.ModifiedTriggers) == 0 &&
 		len(diff.AddedPolicies) == 0 && len(diff.DroppedPolicies) == 0 &&
 		len(diff.ModifiedPolicies) == 0 && len(diff.RLSChanges) == 0 &&
-		!diff.CommentChanged {
+		!diff.CommentChanged && !diff.PersistenceChanged {
 		return nil
 	}
 
@@ -583,7 +588,11 @@ func generateTableSQL(table *ir.Table, targetSchema string, createdTables map[st
 	tableName := ir.QualifyEntityNameWithQuotes(table.Schema, table.Name, targetSchema)
 
 	var parts []string
-	parts = append(parts, fmt.Sprintf("CREATE TABLE IF NOT EXISTS %s (", tableName))
+	createPrefix := "CREATE TABLE IF NOT EXISTS"
+	if table.Unlogged {
+		createPrefix = "CREATE UNLOGGED TABLE IF NOT EXISTS"
+	}
+	parts = append(parts, fmt.Sprintf("%s %s (", createPrefix, tableName))
 
 	// Add columns
 	var columnParts []string
@@ -688,6 +697,27 @@ func constraintDroppedWithColumns(constraint *ir.Constraint, droppedColumnSet ma
 // droppedColumnSet contains column names being dropped from this table; constraints that
 // depend on those columns are skipped because DROP COLUMN already removes them. (#384)
 func (td *tableDiff) generateAlterTableStatements(targetSchema string, collector *diffCollector, droppedTableSet map[string]bool, droppedColumnSet map[string]bool) {
+	// Persistence change (UNLOGGED to LOGGED or vice versa) should emit first
+	// because PostgreSQL rewrites the heap so doing it before column/constraint
+	// changes reduces data movement on subsequent steps
+	if td.PersistenceChanged {
+		tableName := getTableNameWithSchema(td.Table.Schema, td.Table.Name, targetSchema)
+		clause := "SET LOGGED"
+		if td.Table.Unlogged {
+			clause = "SET UNLOGGED"
+		}
+		sql := fmt.Sprintf("ALTER TABLE %s %s;", tableName, clause)
+
+		context := &diffContext{
+			Type:                DiffTypeTablePersistence,
+			Operation:           DiffOperationAlter,
+			Path:                fmt.Sprintf("%s.%s", td.Table.Schema, td.Table.Name),
+			Source:              td.Table,
+			CanRunInTransaction: true,
+		}
+		collector.collect(context, sql)
+	}
+
 	// Drop constraints first (before dropping columns) - already sorted by the Diff operation
 	for _, constraint := range td.DroppedConstraints {
 		// Skip constraints already removed by a dropped column. (#384)

ir/inspector.go

@@ -261,6 +261,7 @@ func (i *Inspector) buildTables(ctx context.Context, schema *IR, targetSchema st
 			Name:        tableName,
 			Type:        tType,
 			Comment:     comment,
+			Unlogged:    table.Relpersistence.Valid && table.Relpersistence.String == "u",
 			Columns:     []*Column{},
 			Constraints: make(map[string]*Constraint),
 			Indexes:     make(map[string]*Index),

ir/ir.go

@@ -63,6 +63,7 @@ type Table struct {
 	PartitionStrategy string                 `json:"partition_strategy,omitempty"` // RANGE, LIST, HASH
 	PartitionKey      string                 `json:"partition_key,omitempty"`      // Column(s) used for partitioning
 	LikeClauses       []LikeClause           `json:"like_clauses,omitempty"`       // LIKE clauses in CREATE TABLE
+	Unlogged          bool                   `json:"unlogged,omitempty"`           // True for UNLOGGED tables
 }
 
 // Column represents a table column

ir/queries/queries.sql

@@ -22,11 +22,12 @@ WHERE
 
 -- GetTables retrieves all tables in the database with metadata
 -- name: GetTables :many
-SELECT 
+SELECT
     t.table_schema,
     t.table_name,
     t.table_type,
-    COALESCE(d.description, '') AS table_comment
+    COALESCE(d.description, '') AS table_comment,
+    c.relpersistence::text AS relpersistence
 FROM information_schema.tables t
 LEFT JOIN pg_namespace n ON n.nspname = t.table_schema
 LEFT JOIN pg_class c ON c.relname = t.table_name AND c.relnamespace = n.oid
@@ -44,7 +45,8 @@ SELECT
     t.table_schema,
     t.table_name,
     t.table_type,
-    COALESCE(d.description, '') AS table_comment
+    COALESCE(d.description, '') AS table_comment,
+    c.relpersistence::text AS relpersistence
 FROM information_schema.tables t
 LEFT JOIN pg_namespace n ON n.nspname = t.table_schema
 LEFT JOIN pg_class c ON c.relname = t.table_name AND c.relnamespace = n.oid

ir/queries/sqlc.yaml

@@ -13,4 +13,4 @@ sql:
         emit_json_tags: true
     database:
       managed: false
-      uri: "postgres://postgres:testpwd1@localhost:5432/sakila"
+      uri: "postgres://postgres:testpwd1@localhost:5432/sakila"

testdata/diff/create_table/add_table_unlogged/diff.sql

@@ -0,0 +1,5 @@
+CREATE UNLOGGED TABLE IF NOT EXISTS events (
+    id integer,
+    payload text NOT NULL,
+    CONSTRAINT events_pkey PRIMARY KEY (id)
+);

testdata/diff/create_table/add_table_unlogged/new.sql

@@ -0,0 +1,4 @@
+CREATE UNLOGGED TABLE public.events (
+    id integer PRIMARY KEY,
+    payload text NOT NULL
+);

testdata/diff/create_table/add_table_unlogged/old.sql

@@ -0,0 +1 @@
+-- Empty schema (no tables)

testdata/diff/create_table/add_table_unlogged/plan.json

@@ -0,0 +1,20 @@
+{
+  "version": "1.0.0",
+  "pgschema_version": "1.9.0",
+  "created_at": "1970-01-01T00:00:00Z",
+  "source_fingerprint": {
+    "hash": "965b1131737c955e24c7f827c55bd78e4cb49a75adfd04229e0ba297376f5085"
+  },
+  "groups": [
+    {
+      "steps": [
+        {
+          "sql": "CREATE UNLOGGED TABLE IF NOT EXISTS events (\n    id integer,\n    payload text NOT NULL,\n    CONSTRAINT events_pkey PRIMARY KEY (id)\n);",
+          "type": "table",
+          "operation": "create",
+          "path": "public.events"
+        }
+      ]
+    }
+  ]
+}

testdata/diff/create_table/add_table_unlogged/plan.sql

@@ -0,0 +1,5 @@
+CREATE UNLOGGED TABLE IF NOT EXISTS events (
+    id integer,
+    payload text NOT NULL,
+    CONSTRAINT events_pkey PRIMARY KEY (id)
+);

testdata/diff/create_table/add_table_unlogged/plan.txt

@@ -0,0 +1,16 @@
+Plan: 1 to add.
+
+Summary by type:
+  tables: 1 to add
+
+Tables:
+  + events
+
+DDL to be executed:
+--------------------------------------------------
+
+CREATE UNLOGGED TABLE IF NOT EXISTS events (
+    id integer,
+    payload text NOT NULL,
+    CONSTRAINT events_pkey PRIMARY KEY (id)
+);

testdata/diff/create_table/set_logged/diff.sql

@@ -0,0 +1 @@
+ALTER TABLE events SET LOGGED;

testdata/diff/create_table/set_logged/new.sql

@@ -0,0 +1,4 @@
+CREATE TABLE public.events (
+    id integer PRIMARY KEY,
+    payload text NOT NULL
+);

testdata/diff/create_table/set_logged/old.sql

@@ -0,0 +1,4 @@
+CREATE UNLOGGED TABLE public.events (
+    id integer PRIMARY KEY,
+    payload text NOT NULL
+);

testdata/diff/create_table/set_logged/plan.json

@@ -0,0 +1,20 @@
+{
+  "version": "1.0.0",
+  "pgschema_version": "1.9.0",
+  "created_at": "1970-01-01T00:00:00Z",
+  "source_fingerprint": {
+    "hash": "b465915d72f5be87a29cb98e6808e1cb91db1525bbb7e17775df4774cd0737da"
+  },
+  "groups": [
+    {
+      "steps": [
+        {
+          "sql": "ALTER TABLE events SET LOGGED;",
+          "type": "table.persistence",
+          "operation": "alter",
+          "path": "public.events"
+        }
+      ]
+    }
+  ]
+}

testdata/diff/create_table/set_logged/plan.sql

@@ -0,0 +1 @@
+ALTER TABLE events SET LOGGED;

testdata/diff/create_table/set_logged/plan.txt

@@ -0,0 +1,13 @@
+Plan: 1 to modify.
+
+Summary by type:
+  tables: 1 to modify
+
+Tables:
+  ~ events
+    ~ events (persistence)
+
+DDL to be executed:
+--------------------------------------------------
+
+ALTER TABLE events SET LOGGED;

testdata/diff/create_table/set_unlogged/diff.sql

@@ -0,0 +1 @@
+ALTER TABLE events SET UNLOGGED;

testdata/diff/create_table/set_unlogged/new.sql

@@ -0,0 +1,4 @@
+CREATE UNLOGGED TABLE public.events (
+    id integer PRIMARY KEY,
+    payload text NOT NULL
+);

testdata/diff/create_table/set_unlogged/old.sql

@@ -0,0 +1,4 @@
+CREATE TABLE public.events (
+    id integer PRIMARY KEY,
+    payload text NOT NULL
+);

testdata/diff/create_table/set_unlogged/plan.json

@@ -0,0 +1,20 @@
+{
+  "version": "1.0.0",
+  "pgschema_version": "1.9.0",
+  "created_at": "1970-01-01T00:00:00Z",
+  "source_fingerprint": {
+    "hash": "cb84b30ef73ee96caeeef3901be4354d9f8aecf303f0fcb9ae70618c1d106761"
+  },
+  "groups": [
+    {
+      "steps": [
+        {
+          "sql": "ALTER TABLE events SET UNLOGGED;",
+          "type": "table.persistence",
+          "operation": "alter",
+          "path": "public.events"
+        }
+      ]
+    }
+  ]
+}

testdata/diff/create_table/set_unlogged/plan.sql

@@ -0,0 +1 @@
+ALTER TABLE events SET UNLOGGED;

testdata/diff/create_table/set_unlogged/plan.txt

@@ -0,0 +1,13 @@
+Plan: 1 to modify.
+
+Summary by type:
+  tables: 1 to modify
+
+Tables:
+  ~ events
+    ~ events (persistence)
+
+DDL to be executed:
+--------------------------------------------------
+
+ALTER TABLE events SET UNLOGGED;