Batching pushes Postgres LISTEN/NOTIFY from 2.9K to 60K writes per second

Sources: DBOS blog, HN 49040296
Summary: DBOS published a benchmark on 2026-07-24 of Postgres LISTEN/NOTIFY as a stream-delivery mechanism. A database trigger firing NOTIFY on every write topped out at 2.9K writes per second with minimal CPU, memory, and I/O use, because Postgres takes a global exclusive lock during commit to preserve notification ordering, which serializes writes and blocks group commit. Buffering notifications in memory and flushing them in periodic batch transactions, with polling as a reliability fallback, reached 60K writes per second at 15 to 100 milliseconds of latency and saturated Postgres CPU. The figures are the vendor's own and were not independently reproduced.
Why it matters: The published bottleneck is a commit-time global lock, not throughput of the notification path, which tells you the fix is fewer NOTIFY calls rather than more database capacity.