Postgres LISTEN/NOTIFY Actually Scales

2026-07-27

Postgres LISTEN/NOTIFY can bottleneck because every notifying transaction acquires a global exclusive lock through commit, serializing writes, and preventing group commit. Buffering notifications in memory, flushing them in batches, and using infrequent polling as a reliability fallback increased throughput from 2,900 to 60,000 stream writes per second while maintaining 15–100 ms latency.