Core conceptsbeginner
Autovacuum
The background process that reclaims space from dead tuples and refreshes planner statistics without a human running VACUUM by hand.
What this means
The cleanup crew that runs on its own. As rows are updated or deleted, Postgres leaves behind dead row versions that still take up space; autovacuum comes around in the background, reclaims that space, and refreshes the statistics the planner relies on, all without anyone typing VACUUM by hand.
Why it matters operationally
When autovacuum falls behind, tables bloat, indexes slow down, and transaction-ID wraparound risk climbs, it is a first-order operational concern.
Related errors
Mentioned from
Where it lives in the source
src/backend/postmaster/autovacuum.c