PgBouncer 1.26.0 Documentation

Source: https://www.pgbouncer.org/

This manual is based on PgBouncer 1.26.0, released on 2026-09-23. See the release notes for the changes from earlier versions.

pgbouncer is a PostgreSQL connection pooler. Applications connect to pgbouncer as they would to a PostgreSQL server. pgbouncer creates a server connection or reuses an existing connection.

pgbouncer reduces the performance cost of opening new PostgreSQL connections.

To preserve transaction semantics, pgbouncer supports these connection pooling modes:

• Session pooling: PgBouncer assigns a server connection to a client for its entire session. When the client disconnects, the connection returns to the pool. This is the default mode and changes connection assignment least often.
• Transaction pooling: PgBouncer assigns a server connection only during a transaction. When the transaction ends, the connection returns to the pool.
• Statement pooling: The connection returns to the pool immediately after each query. This mode changes connection assignment most often and does not allow multi-statement transactions.