Cookbook recipe

Find your slowest queries with pg_stat_statements

Applies to PostgreSQL 13–17 Last reviewed May 2026 Grounded in source

What This Is

A production experience capsule based on real incident patterns.

Why It Matters

Builds production judgment under pressure.

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Estimated investigation4 min

Scenario

The database feels slow but you do not know which queries are to blame. pg_stat_statements ranks every normalized query by total time so you can target the real offenders. Diagnose it Enable the extension, then rank…

Investigation Path

The database feels slow but you do not know which queries are to blame. pg_stat_statements ranks every normalized query by total time so you can target the real offenders.

Diagnose it

Enable the extension, then rank by total execution time:

CREATE EXTENSION IF NOT EXISTS pg_stat_statements;

SELECT queryid, calls, round(total_exec_time) AS total_ms,
       round(mean_exec_time, 2) AS mean_ms, rows
FROM pg_stat_statements
ORDER BY total_exec_time DESC
LIMIT 20;

Why it happens

Total wall-clock cost is calls * mean time. A fast query called millions of times can hurt more than one slow report. Ranking by total time finds what actually consumes the server.

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