[datlechin]

Summary

• Presto is a connection type of its own, served by the Trino plugin as a variant (additionalDatabaseTypeIds), with its own icon, a presto:// scheme and jdbc:presto:// import.
• The Presto client sends X-Presto-* headers and no client capabilities header, which Presto does not define.
• Presto connects on SELECT 1 and reads its version from system.runtime.nodes: it has no version().
• Presto lists materialized views from information_schema.materialized_views and skips the table comment query: it has neither system.metadata table.
• Presto browses its leading rows with LIMIT and no page navigation: OFFSET is off by default, and the grammar takes neither FETCH NEXT nor LIMIT before OFFSET. A variant now keeps its curated pagination over its plugin's grammar, as it already does for case sensitivity.
• Presto offers no COMMENT ON edits, which its grammar lacks.
• Arrays, maps and rows that Presto sends as JSON text read as JSON. KHyperLogLog and kllsketch read as binary.
• An installed plugin that predates a variant no longer serves it: a Presto connection on a Trino plugin without Presto asks for the plugin update instead of sending Trino headers.
• A Trino or Presto URL path reads as /catalog/schema on import and is written back that way on copy.
• Errors and the server version name the right engine.
• An iPhone import of a Mac export marks a Presto connection Mac only instead of unsupported.
• The Trino curated entry moved to PluginMetadataRegistry+TrinoDefaults.swift, next to Presto's.
• apple/scripts/probes/check-presto-protocol.sh checks each Presto fact above against a stock coordinator.
• Updated on purpose: PluginMetadataRegistryTypeCountTests and SQLLexicalReadingsTests list Presto, CellExpressionVocabularyTests expects no UPDATE ... DEFAULT on Presto, SQLDDLFallbackPolicyTests classifies Presto as an engine with SQL DDL, MacOnlyImportRowTests covers Presto.

Test plan

• New TableProTrinoCoreTests: Presto headers, no capabilities header, Presto response headers, introspection SQL, connect and version statements, structured values sent as text, sketch types.
• PluginMetadataRegistryVariantTests: Presto keeps LIMIT paging when the Trino plugin registers it, and a Presto browse writes no OFFSET or FETCH. PluginManagerVariantAccessorTests: a Trino plugin without Presto does not serve a Presto connection. ConnectionURLParserJDBCTests and ConnectionURLFormatterTests: presto://, jdbc:presto:// and /catalog/schema paths.
• The probe against prestodb/presto:latest (0.299): every check passes, including connect, catalogs, schemas, tables, a LIMIT browse, the EXPLAIN variants and Cancel Query (DELETE on nextUri leaves the query FAILED).

Fixes #3598