VOOZH about

URL: https://dev.to/bertrand_hartwig_309d1958/postgresql-which-queries-should-you-optimize-first-5ga

⇱ PostgreSQL: Which Queries Should You Optimize First? - DEV Community


When investigating PostgreSQL performance, the usual starting point is pg_stat_statements. From there, many teams sort queries by mean_exec_time or total_exec_time and start optimizing the first rows in the list.

That approach is simple, but it often leads to the wrong priorities.

A query that takes five seconds but runs twice a day is not necessarily more important than a query that takes five milliseconds and runs millions of times. Conversely, a query with a high total execution time may simply be a normal core workload query, not necessarily the best optimization target.

The real question is not:

Which query is the slowest?

It is:

Which query has the highest operational impact and the clearest optimization potential?

This is the principle behind the query-ranking algorithm implemented in pgAssistant.

Read the full post here