Under-indexing

Nikolay and Michael discuss under-indexing — how to tell if this applies to you, some general and specific cases, as well as some tricky ones. 
 
Here are some links to things they mentioned:

• Indexes (docs) https://www.postgresql.org/docs/current/indexes.html 
• random_page_cost https://postgresqlco.nf/doc/en/param/random_page_cost/
• Sequential scans https://www.pgmustard.com/docs/explain/sequential-scan  
• pg_stat_user_tables https://pgpedia.info/p/pg_stat_user_tables.html 
• pg_stat_statements https://www.postgresql.org/docs/current/pgstatstatements.html
• auto_explain https://www.postgresql.org/docs/current/auto-explain.html 
• Our episode on slow queries https://postgres.fm/episodes/slow-queries-and-slow-transactions 
• Our episode on query macro analysis https://postgres.fm/episodes/macro-query-analysis-intro
• Running 10 Million PostgreSQL Indexes In Production (And Counting) https://www.heap.io/blog/running-10-million-postgresql-indexes-in-production 
• Faceting large result sets in PostgreSQL https://www.cybertec-postgresql.com/en/faceting-large-result-sets/ 
• Our episode on …

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