Understanding and Fixing Autovacuum

on YouTube ↗49m

" summary

Explains why autovacuum misjudges work and lists concrete diagnostics and fixes: check OS tools (top/ps), inspect wait_event in pg_stat_activity and phase in pg_stat_progress_vacuum, watch IO/CPU, and detect long transactions, prepared transactions or orphaned replication slots. Fixes include raising vacuum_cost_limit (or lowering autovacuum_vacuum_cost_delay), increasing autovacuum_max_workers while scaling the cost limit, per-table autovacuum_vacuum_scale_factor, reindexing or dropping corrupted indexes, and avoiding PG_STAT_RESET; notes v12 and v16 behavior changes that affect live tuning.

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" chapters (7)

1. 0:00Introduction
2. 1:20How autovacuum works
3. 7:04When autovacuum fails
4. 13:59Fixing slow or stuck vacuum
5. 26:16Fixing repeated vacuuming
6. 30:26Handling skipped tables
7. 40:10Q&A and conclusion

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