PostgreSQL Connection Pooling Under Pressure

Deep dive into the real-world pain points of PostgreSQL connection pooling — why transaction-mode PgBouncer breaks prepared statements (and the DEALLOCATE ALL / server-side vs extended query protocol fixes), how to calculate optimal pool size using the formula from the PostgreSQL wiki adjusted for multi-tenant workloads, session pinning traps with SET statements and advisory locks, and the monitoring queries that reveal pool saturation before your p99 latency spikes. Includes comparison of PgBouncer vs pgcat vs Supavisor for modern cloud-native stacks.