feat: add schema comments and materialized view support#160
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stephanhaeuslschmid wants to merge 3 commits into
Open
feat: add schema comments and materialized view support#160stephanhaeuslschmid wants to merge 3 commits into
stephanhaeuslschmid wants to merge 3 commits into
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…ools Add PostgreSQL COMMENT support to list_objects and get_object_details: - list_objects: include obj_description() for tables, views, and materialized views - get_object_details: include col_description() for column comments and obj_description() for table/view/materialized view comments Add materialized view as a new object_type: - list_objects: query pg_class with relkind='m' for materialized views - get_object_details: query pg_attribute for columns (since materialized views are not in information_schema.columns) This enables LLMs using the MCP server to discover schema documentation stored as COMMENT ON TABLE/VIEW/COLUMN statements, which is the standard PostgreSQL mechanism for schema documentation. Closes crystaldba#71
These pg_catalog functions are read-only and needed for the schema comment feature to work in restricted mode.
Add "PostgreSQL" keyword to all tool descriptions so LLM search can find them. Make get_object_details and list_objects descriptions explicit about returned data (columns, comments, constraints, indexes).
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Summary
list_objectsandget_object_detailsnow include PostgreSQLCOMMENT ONmetadata viaobj_description()andcol_description()frompg_catalogobject_type='materialized_view'for both tools, queryingpg_class(since materialized views are not ininformation_schema)Motivation
LLMs using this MCP server to explore databases cannot currently see schema documentation stored as
COMMENT ON TABLE/VIEW/COLUMNstatements — the standard PostgreSQL mechanism for documenting columns (units, enums, business logic). This makes it much harder for LLMs to correctly interpret data.Similarly, materialized views (commonly used for analytics/reporting layers) are invisible because
information_schema.tablesdoes not include them.Changes
list_objects:obj_description()ascommentfieldobject_type='materialized_view'queriespg_class WHERE relkind = 'm'with commentsget_object_details:col_description()ascommentfieldbasicsection viaobj_description()pg_attribute(notinformation_schema.columns)Example
These comments now appear in
list_objectsandget_object_detailsresponses, giving LLMs the context they need to write correct queries.Closes #71