Diagnosing Bloat and Vacuum Strategy
Understand how MVCC creates table and index bloat, how to measure it, and how to tune autovacuum to keep performance high.
MVCC and Dead Tuples
PostgreSQL uses MVCC: updates and deletes leave behind old row versions called dead tuples. Until they are cleaned up, they occupy space and slow scans. This wasted space is bloat.
What VACUUM Does
VACUUM reclaims dead tuples for reuse and updates visibility information. It usually does not return space to the OS; VACUUM FULL does but rewrites the whole table and takes a strong lock.
All lessons in this course
- Holistic Performance Tuning
- Advanced Monitoring and Alerting
- Future Trends in PostgreSQL
- Diagnosing Bloat and Vacuum Strategy