Nikolay and Michael discuss a common question — why Postgres isn't using an index, and what you can do about it!
Here are some links to things they mentioned:
- Why isn’t Postgres using my index? (blog post by Michael) https://www.pgmustard.com/blog/why-isnt-postgres-using-my-index
- Why isn’t Postgres using my functional index? (Stack Exchange question from Brent Ozar) https://dba.stackexchange.com/questions/336019/why-isnt-postgres-using-my-functional-index
- enable_seqscan (and similar parameters) https://www.postgresql.org/docs/current/runtime-config-query.html
- Crunchy Bridge changed random_page_cost to 1.1 https://docs.crunchybridge.com/changelog#postgres_random_page_cost_1_1
- Make indexes invisible (trick from Haki Benita) https://hakibenita.com/sql-tricks-application-dba#make-indexes-invisible
- ANALYZE https://www.postgresql.org/docs/current/sql-analyze.html
- Statistics used by the planner https://www.postgresql.org/docs/current/planner-stats.html
- Our episode on query hints https://postgres.fm/episodes/query-hints
- transaction_timeout (commit for Postgres 17) https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=51efe38cb92f4b15b68811bcce9ab878fbc71ea5
- What’s new in the Postgres 16 query planner / optimizer (blog post by David Rowley) https://www.citusdata.com/blog/2024/02/08/whats-new-in-postgres-16-query-planner-optimizer/
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What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc!
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Postgres FM is brought to you by:
- Nikolay Samokhvalov, founder of Postgres.ai
- Michael Christofides, founder of pgMustard
With special thanks to:
- Jessie Draws for the amazing artwork