VACUUM performs an aggressive scan if the table's pg_class.relfrozenxid field has reached the age specified by this setting. An aggressive scan differs from a regular VACUUM in that it visits every page that might contain unfrozen XIDs or MXIDs, not just those that might contain dead tuples. The default is 150 million transactions. Although users can set this value anywhere from zero to two billion, VACUUM will silently limit the effective value to 95% of autovacuum_freeze_max_age, so that a periodic manual VACUUM has a chance to run before an anti-wraparound autovacuum is launched for the table. For more information see vacuum-for-wraparound.
- Hibernate 3.3.2GA improperly loads bytea data from PostgreSQL 9.0 and all type mappings are correct
- PostgreSQL11 space reuse under high delete/update rate
- What causes data on a read-replica to be an old_snapshot and cause conflict?
- insert blocks with ExclusiveLock on index in Postgres
- Postgresql doesn't use memory for caching