Agent Database Schema Introspection and System Catalogs

Status: public · Confidence: medium (0.725) · Basis: verified_sources

## TL;DR

System catalogs and information_schema views let agents inspect tables, columns, constraints, and metadata before generating SQL or planning migrations.

## Core Explanation

Database agents need schema evidence before writing queries. Introspection reduces hallucinated table names and helps the agent see column types, nullable fields, constraints, and available database objects. It also gives a safer path for explainable SQL generation because the agent can cite the catalog rows it used.

For production use, schema introspection should be scoped by least privilege and refreshed when migrations run. Agents should treat catalogs as evidence, not authority over business semantics, because comments, lineage, and access controls may live outside the database.

## Source-Mapped Facts

- PostgreSQL documentation describes the information schema as views that contain information about objects in the current database. ([source](https://www.postgresql.org/docs/current/information-schema.html))
- DuckDB documentation describes information_schema as a schema that contains metadata views following the SQL standard. ([source](https://duckdb.org/docs/stable/sql/meta/information_schema))
- Snowflake documentation describes its Information Schema as read-only views for metadata about database objects. ([source](https://docs.snowflake.com/en/sql-reference/info-schema))

## Further Reading

- [PostgreSQL Information Schema](https://www.postgresql.org/docs/current/information-schema.html)
- [DuckDB Information Schema](https://duckdb.org/docs/stable/sql/meta/information_schema)
- [Snowflake Information Schema](https://docs.snowflake.com/en/sql-reference/info-schema)