A server parameter controlling the number of autovacuum workers

autovacuum_max_workers is a configuration parameter specifying the maximum number of autovacuum processes which can run simultaneously.

autovacuum_max_workers was added in PostgreSQL 8.3.


autovacuum_max_workers controlls the actual number of autovacuum processes which can be launched as the same time. The autovacuum launcher itself is not included in this number.

Note that autovacuum_max_workers is a global cluster setting, not per-database. This means that depending on the autovacuum_max_workers setting and the number of databases present, autovacuum may not run on all databases simultaenously.

Default value

The default value for autovacuum_max_workers is: 3.

Change history


GUC configuration item, Vacuuming

See also

autovacuum_work_mem max_worker_processes