Postgres: The First Experience

A compact reference with working examples: data types, window functions, common table expressions, JSON support, triggers, PL/pgSQL, backups, roles, and high availability.

GoalKicker

A deep look at how PostgreSQL works under the hood. It explains isolation and MVCC, the buffer cache and WAL, locks, query execution and planning, and every index type from B-tree to BRIN.

Egor Rogov

The official PostgreSQL manual in a single file. It includes the tutorial, the full SQL language reference, server administration, client interfaces, and server programming.

PostgreSQL Global Development Group