System catalogs

The system catalogs are the place where users can access schema metadata, such as information about tables and columns, and other bookkeeping information. Subsalt supports two standard system catalogs: pg_catalog and information_schema. All catalog tables are read-only, and can be queried with standard SQL statements.

pg_catalog

pg_catalog is Postgres' system catalog and contains information about tables, namespaces, data types, and many other entities. Subsalt supports the full schema for all tables for compatibility reasons, though some values don't apply to generative databases and aren't populated.

information_schema

information_schema is the ANSI SQL standard system catalog and contains information about entities common to all relational databases (tables, columns, etc). Subsalt supports the set of tables supported by Postgres.