[Solved] A query to find slow queries is:SELECT query, mean_time FROM pg_stat_statements ORDER BY mean_time DESC;But it returns no rows. What could be wrong? | PostgreSQL

PostgreSQL - Performance Tuning

A query to find slow queries is:

SELECT query, mean_time FROM pg_stat_statements ORDER BY mean_time DESC;

But it returns no rows. What could be wrong?

ANo queries have been executed since pg_stat_statements was enabled

BThe query syntax is incorrect

Cpg_stat_statements is disabled in postgresql.conf

DThe user lacks SELECT permission on pg_stat_statements

Step-by-Step Solution

Solution:

Step 1: Check if queries have run
If no queries have run since enabling, the stats table will be empty.
Step 2: Confirm query syntax and permissions
The syntax is correct and permissions usually allow reading this view.
Final Answer:
No queries have been executed since pg_stat_statements was enabled -> Option A
Quick Check:
Empty pg_stat_statements = no queries run yet [OK]

Quick Trick: Run some queries first to populate pg_stat_statements [OK]

Common Mistakes:

Master "Performance Tuning" in PostgreSQL

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A query to find slow queries is: