postgres=# select * from sessions where video_id = 'g9yl3zE9MlI';
Vibe Hacking Postgres
Generic workshop near the start of the MultiXact standby-deadlock thread.
session summary
Responding to audience interest in locking, the group investigated a Postgres 17 standby hang introduced when a one-millisecond MultiXact polling sleep was replaced with condition variables. A reported workload could drive replica TPS to zero. They reconstructed the locking protocol, used AI to inspect the patch and report, and realized the likely failure is a true deadlock: a query waits for MultiXact replay while holding the heap page needed by startup. They planned timeout instrumentation and stronger diagnostics.
timecodes
- Audience chooses locking as the topic
- MultiXact basics and foreign-key locking
- SLRU storage and the old polling sleep
- Condition-variable optimization in Postgres 17
- Replica TPS drops to zero in the reported workload
- Why standby replay changes the concurrency model
- Timeout workaround versus a real fix
- Identifying the heap-page deadlock