PostgreSQL Database Sizes and Temp File Usage
Shows each database's size with rollback, deadlock and temp file stats. Used for growth tracking and a quick health summary.
SELECT d.datname,
pg_size_pretty(pg_database_size(d.datname)) AS size,
s.xact_commit, s.xact_rollback, s.deadlocks,
s.temp_files, pg_size_pretty(s.temp_bytes) AS temp_size
FROM pg_database d
JOIN pg_stat_database s ON s.datname = d.datname
WHERE NOT d.datistemplate
ORDER BY pg_database_size(d.datname) DESC;Verify in a staging environment prior to running in production. This is a read-only diagnostic query; it does not acquire exclusive locks.
- 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.x).
- Exercise caution with mutating actions (e.g., terminating sessions or dropping indexes) referenced in the notes section.
Engineering Triad: Related Runbooks & Incident Response
Which production incidents and emergency drills execute this script as a diagnosis step?
Other POSTGRESQL Diagnostic Scripts
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Lists queries running longer than a minute, their wait events, and idle-in-transaction sessions that block vacuum. The first script to run during a performance incident.
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Uses pg_blocking_pids to pair blocked and blocking sessions with their queries and wait times. Shows the root cause of a lock chain in seconds.
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.
Find Unused Indexes in PostgreSQL
Lists never-scanned indexes that are neither unique nor primary keys, with their sizes. Surfaces cleanup candidates to cut write overhead and disk usage.