PostgreSQL Connection Pool Optimization: Slashing Latency and Memory with PgBouncer

Unlike MySQL's threaded concurrency model, PostgreSQL employs an operating system process-per-connection architecture. Each connection forks a separate OS process consuming 5MB to 15MB of RAM plus kernel scheduling overhead. In large microservices fleets, unmanaged connection pools will swiftly trigger database resource exhaustion.

1. PgBouncer Transaction Pooling Efficiency

PgBouncer is a high-performance lightweight connection pooler written in C. Among its three modes (Session, Transaction, Statement), Transaction Pooling delivers the highest efficiency: assigning an actual database connection strictly for the duration of a transaction, returning it to the pool immediately upon COMMIT or ROLLBACK.