Postgres Internals Hiding in Plain Sight
8 days ago
- #SQL
- #Database Internals
- #Postgres
- Postgres has internal tables that store data about itself, known as the Postgres catalog.
- The psql command-line tool provides shortcuts (like \d, \di, \dx) to access catalog information easily.
- Important Postgres catalog views include pg_stat_activity, pg_stat_statements, pg_stat_database, pg_locks, and pg_stat_user_tables.
- These views help monitor database activity, query performance, locks, and table/index usage.
- Postgres catalog tables (e.g., pg_class, pg_type, pg_proc, pg_attribute) store metadata about tables, data types, functions, and columns.
- The pg_catalog schema contains all system tables, which can be explored using psql's ECHO_HIDDEN or -E flag.
- Understanding Postgres internals helps troubleshoot performance issues, optimize queries, and manage database objects.