On Wed, Jun 29, 2022 at 09:31:58PM +0200, Mikkel Lauritsen wrote: > In short I'm running PostgreSQL 14.1 on Linux on a small test machine with should try to upgrade to 14.4, for $reasons > Is there any feasible way to find out what it is that causes Postgres to > start doing slow updates? My guess would be a buffer filling up or something > similar, but the regularity between runs paired with the irregular lengths > of the fast and slow phases in each run doesn't really seem to fit with > this. Set log_checkpoints=on, log_autovacuum_min_duration=0, log_lock_waits=on, and enable autoexplain with auto_explain.log_nested_statements=on. Then see what's in the logs when that happens. @hackers: the first two of those are enabled by default in 15dev, and this inquiry seems to support that change. -- Justin
