How to Tune PostgreSQL Autovacuum for High-Write Mobile Backends

Mobile backends generating constant upserts, session updates, and event streams can overwhelm PostgreSQL's default autovacuum settings, leading to excessive dead tuple buildup and query performance degradation. PostgreSQL's MVCC model creates a new row version on every UPDATE, meaning old versions accumulate as dead tuples until vacuum clears them. The default autovacuum trigger — set at 20% of total rows — is too lenient for high-churn tables, allowing hundreds of thousands of dead tuples to pile up before cleanup begins. Engineers can apply per-table storage parameter overrides, such as lower scale factors and zero cost delay, to make autovacuum fire more aggressively on critical tables. Accurate bloat detection requires the pgstattuple extension rather than relying on pg_stat_user_tables, whose dead tuple counts lag significantly under sustained write load.