PostgreSQL Dead Tuples, Bloat and Autovacuum Health Check
Shows dead tuple ratio and last vacuum/analyze times per table. Helps you find tables where autovacuum settings are not keeping up.
SELECT schemaname, relname,
n_live_tup, n_dead_tup,
round(100.0 * n_dead_tup / NULLIF(n_live_tup + n_dead_tup, 0), 2) AS dead_pct,
last_vacuum, last_autovacuum, last_autoanalyze,
pg_size_pretty(pg_total_relation_size(relid)) AS total_size
FROM pg_stat_user_tables
WHERE n_dead_tup > 10000
ORDER BY n_dead_tup DESC
LIMIT 30;If `dead_pct` is consistently above 20%, consider lowering `autovacuum_vacuum_scale_factor` for that specific table.
- This script is designed for read-only diagnostics; it does not alter schema or modify data directly.
- Prior to executing on production systems under high load, verify the target database version (Min. Version: 9.4).
- Exercise caution with mutating actions (e.g., terminating sessions or dropping indexes) referenced in the notes section.
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