autovacuum
No restart — takes effect on reloadboolean (on/off)
The master switch for the background autovacuum daemon.
What it does
autovacuum turns the background process on or off. That daemon reclaims space from dead row versions, refreshes planner statistics, and prevents transaction-ID wraparound. With it on (the default), PostgreSQL keeps tables healthy without manual VACUUM.
How to tune it
Leave it on. Turning autovacuum off is almost always a mistake — tables bloat, statistics go stale, and wraparound becomes a real risk. If autovacuum can't keep up, the fix is to make it more aggressive (lower scale factors, higher cost limit), not to disable it. Note that even when 'off', PostgreSQL still force-vacuums to avert wraparound.
FAQ
- Should I ever turn autovacuum off?
- Practically never for a whole cluster. At most you might pause it on a specific table during a bulk load and vacuum manually afterward. Leaving it off invites bloat, stale stats, and transaction-ID wraparound.