PostgreSQL 12 High Availability Cookbook - Third Edition

Checking the pg_stat_statements view

We mentioned in another recipe that logging every query on a highly available database that handles high volumes of query traffic is undesirable. DBAs often solve this problem by only logging slow queries, by setting log_min_duration_statement to a reasonable number of milliseconds in postgresql.conf. Later, only queries that cross this threshold are logged, along with binding parameters if the query was a prepared statement.

We strongly encourage this practice, as it is invaluable for catching outlying queries that could benefit from optimization. Unfortunately, faster queries are still invisible to us. Worse, queries that execute often probably have their data sources cached in memory, so it's unlikely ...