VACUUM

VACUUM and Autovacuum

Why PostgreSQL needs VACUUM to reclaim dead tuples and prevent transaction ID wraparound, and how the autovacuum daemon automates that maintenance.

What is MVCC (Multi-Version Concurrency Control)?

MVCC (Multi-Version Concurrency Control) is a concurrency-control technique where the database keeps multiple versions of a row so readers see a consistent sna…

What is the VACUUM Process in PostgreSQL?

VACUUM is a PostgreSQL maintenance operation that reclaims storage occupied by dead tuples — rows left behind by UPDATE and DELETE under PostgreSQL's MVCC mode…

What Causes Table Bloat and How Do You Fix It?

Table bloat is the accumulation of dead or wasted space inside a table's data pages — usually because updates and deletes leave dead tuples faster than autovac…

How Does PostgreSQL Clean Up Dead Tuples?

PostgreSQL cleans up dead tuples — old row versions left behind by UPDATE and DELETE under MVCC — through VACUUM (run manually or by the autovacuum daemon), wh…

What is Index Bloat and When Should You Reindex?

Index bloat is wasted space inside a B-tree index caused by deleted or updated entries whose slots are not fully compacted back, and the fix is to run REINDEX…