Postgres FM

Nikolay and Michael discuss Postgres health checks — what they are, things to include, how often makes sense, and whether improvements to Postgres would increase or decrease the need for them. Here are some links to things they mentioned:MOT (car test in the UK) https://en.wikipedia.org/wiki/MOT_test Let's make PostgreSQL multi-threaded (discussion started by Heikki) https://www.postgresql.org/message-id/flat/31cc6df9-53fe-3cd9-af5b-ac0d801163f4%40iki.fi postgres-checkup https://gitlab.com/postgres-ai/postgres-checkup Why upgrade https://why-upgrade.depesz.com/  Related episodes: Default configuration https://postgres.fm/episodes/default-configurationIndex maintenance https://postgres.fm/episodes/index-maintenanceBloat https://postgres.fm/episodes/bloatMonitoring checklist https://postgres.fm/episodes/monitoring-checklistpg_stat_statements https://postgres.fm/episodes/pg_stat_statementsBackups https://postgres.fm/episodes/backups~~~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!~~~Postgres FM is brought to you by:Nikolay Samokhvalov, founder of Postgres.aiMichael Christofides, founder of pgMustardWith special thanks to:Jessie Draws for the amazing artwork 

Nikolay and Michael discuss the superuser role in PostgreSQL — what it is, how and when it shouldn’t be used, and whether most cloud providers are right to not give us it (no prizes for guessing). Here are some links to things they mentioned:superuser (docs) https://www.postgresql.org/docs/current/role-attributes.html#id-1.6.9.6.2.1.2.1.1Crunchy Data PostgreSQL Security Technical Implementation Guide (STIG) https://www.crunchydata.com/blog/crunchy-data-postgresql-security-technical-implementation-guide-now-availableSupabase docs (unsupported operations) https://supabase.com/docs/guides/database/postgres/roles-superuserCrunchy Data docs https://docs.crunchybridge.com/concepts/usersRDS docs https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Appendix.PostgreSQL.CommonDBATasks.htmlCloud SQL docs https://cloud.google.com/sql/docs/postgres/usersAzure docs https://learn.microsoft.com/en-us/azure/postgresql/single-server/concepts-serversRoles, Privileges, and Security (talk by Ryan Booz) https://www.youtube.com/watch?v=mtPM3iZFE04~~~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!~~~Postgres FM is brought to you by:Nikolay Samokhvalov, founder of Postgres.aiMichael Christofides, founder of pgMustardWith special thanks to:Jessie Draws for the amazing artwork 

Nikolay and Michael discuss transaction_timeout (a recently committed addition for Postgres 17) — what it's for, how to get around not having it already, and whether it will replace the need to set statement_timeout globally in future. Here are some links to things they mentioned:transaction_timeout (devel docs) https://www.postgresql.org/docs/devel/runtime-config-client.html#GUC-TRANSACTION-TIMEOUTCommit: https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=51efe38cb92f4b15b68811bcce9ab878fbc71ea5 Mailing list thread: https://www.postgresql.org/message-id/flat/CAAhFRxiQsRs2Eq5kCo9nXE3HTugsAAJdSQSmxncivebAxdmBjQ%40mail.gmail.com  Hacking Postgres session on Postgres TV where work started https://www.youtube.com/live/WLoMpg8A4WU?t=50 Our first ever episode, on slow queries and slow transactions https://postgres.fm/episodes/slow-queries-and-slow-transactions statement_timeout (v7.3) https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-STATEMENT-TIMEOUT idle_in_transaction_session_timeout (v9.6) https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-IDLE-IN-TRANSACTION-SESSION-TIMEOUT idle_session_timeout (v14) https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-IDLE-SESSION-TIMEOUT ~~~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!~~~Postgres FM is brought to you by:Nikolay Samokhvalov, founder of Postgres.aiMichael Christofides, founder of pgMustardWith special thanks to:Jessie Draws for the amazing artwork 

Michael and Nikolay are joined by Andrew Atkinson, author of High Performance PostgreSQL for Rails, to discuss how Rails and Postgres work together — where the limits are, how people use the ORM, things that are improving, and some things we can do as a Postgres community to make it even better. Here are some links to things they mentioned:Planet Argon survey https://rails-hosting.com/2022/#databasesActive Record https://guides.rubyonrails.org/active_record_basics.htmlPostgreSQL specific usage of Active Record https://guides.rubyonrails.org/active_record_postgresql.htmlMultiple Databases with Active Record https://guides.rubyonrails.org/active_record_multiple_databases.htmlschema.rb vs structure.sql https://blog.appsignal.com/2020/01/15/the-pros-and-cons-of-using-structure-sql-in-your-ruby-on-rails-application.htmlactiverecord-clean-db-structure (Ruby gem by Lukas Fittl) https://github.com/lfittl/activerecord-clean-db-structureGitLab’s migration_helpers.rb https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/database/migration_helpers.rbSQLite https://www.sqlite.orgPlanetScale’s foreign key support announcement video https://twitter.com/PlanetScale/status/1732070818958500083DoorDash Engineering Blog https://doordash.engineering/blograils-pg-extras https://github.com/pawurb/rails-pg-extrasBenoit Tigeot testing Peter Geoghegan improvement for large IN lists https://gist.github.com/benoittgt/ab72dc4cfedea2a0c6a5ee809d16e04dHigh Performance PostgreSQL for Rails (Andy’s book, 35% discount code “postgres.fm”) https://pragprog.com/titles/aapsql/high-performance-postgresql-for-railsAndy’s blog and website https://andyatkinson.com~~~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!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith special thanks to:Jessie Draws for the elephant artwork 

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.htmlStatistics 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/ ~~~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!~~~Postgres FM is brought to you by:Nikolay Samokhvalov, founder of Postgres.aiMichael Christofides, founder of pgMustardWith special thanks to:Jessie Draws for the amazing artwork 

Nikolay and Michael discuss the overhead of pg_stat_statements and pg_stat_kcache — mostly focusing on some interesting things Nikolay found while stress-testing some large spot instances up to and beyond 2m TPS(!)  Here are some links to things they mentioned:pg_stat_statements https://www.postgresql.org/docs/current/pgstatstatements.htmlpg_stat_kcache https://github.com/powa-team/pg_stat_kcachepg_stat_statements overhead estimate in pganalyze FAQs https://pganalyze.com/faqWhat is the performance impact of pg_stat_statements? (DBA Stack Exchange answer with several links) https://dba.stackexchange.com/questions/303503/what-is-the-performance-impact-of-pg-stat-statementsTowards Millions TPS (blog post by Alexander Korotkov) https://akorotkov.github.io/blog/2016/05/09/scalability-towards-millions-tpsPostgres.ai blog post with links to benchmarks https://postgres.ai/blog/20240127-postges-ai-botpostgresql_cluster https://github.com/vitabaks/postgresql_clusterpg_wait_sampling https://github.com/postgrespro/pg_wait_samplingpg_stat_kcache issue, discussion, and fast resolution https://github.com/powa-team/pg_stat_kcache/issues/41 log_statement_sample_rate https://postgresqlco.nf/doc/en/param/log_statement_sample_rate/ auto_explain.sample_rate https://www.postgresql.org/docs/current/auto-explain.html#id-1.11.7.14.5.3.13.1.3pg_stat_statements performance penalty on Intel much higher than on AMD https://gitlab.com/postgres-ai/postgresql-consulting/tests-and-benchmarks/-/issues/52~~~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!~~~Postgres FM is brought to you by:Nikolay Samokhvalov, founder of Postgres.aiMichael Christofides, founder of pgMustardWith special thanks to:Jessie Draws for the amazing artwork 

Michael is joined by Markus Winand, creator of use-the-index-luke.com and modern-sql.com, and author of SQL Performance Explained, to discuss Modern SQL — what Markus means by it, why it's important, some benefits, some examples, and at least one phrase that should be on a t-shirt. Here are some links to things they mentioned:Modern SQL (site) https://modern-sql.comUse the index, Luke! (site) https://use-the-index-luke.comSQL Performance Explained (book) https://sql-performance-explained.comOur episode on NULLs https://postgres.fm/episodes/nulls-the-good-the-bad-the-ugly-and-the-unknownIS DISTINCT FROM (null-safe not equals comparison) https://modern-sql.com/caniuse/is-distinct-fromUNIQUE NULLS DISTINCT https://modern-sql.com/caniuse/unique-nulls-distinctModernes SQL ist mehr als SELECT * FROM (a German language podcast Markus was on recently) https://engineeringkiosk.dev/podcast/episode/99-modernes-sql-ist-mehr-als-select-from-mit-markus-winandMarkus’ website https://winand.at~~~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!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith special thanks to:Jessie Draws for the elephant artwork 

Michael is joined by Chelsea Dole, Staff Software Engineer and Tech Lead of the Data Storage Team at Brex, to discuss bloat. They cover what it is, why it's a problem, strategies for minimising it, and the options when it's really bad. Here are some links to things they mentioned:Managing your tuple graveyard (talk by Chelsea) https://www.youtube.com/watch?v=gAgbzvGT6ckpgstattuple https://www.postgresql.org/docs/current/pgstattuple.html pg_class https://www.postgresql.org/docs/current/catalog-pg-class.html Bloat in PostgreSQL: a taxonomy (talk by Peter Geoghegan) https://youtube.com/watch?v=JDG4bMHxCH8 It's Not You, It's Me: Breaking Up with Massive Tables via Partitioning (talk by Chelsea) https://youtube.com/watch?v=TafwSuLNxe8 pg_repack https://github.com/reorg/pg_repackpg_squeeze https://github.com/cybertec-postgresql/pg_squeeze VACUUM https://www.postgresql.org/docs/current/sql-vacuum.htmlautovacuum https://www.postgresql.org/docs/current/runtime-config-autovacuum.html CLUSTER https://www.postgresql.org/docs/current/sql-cluster.html HOT updates https://www.postgresql.org/docs/current/storage-hot.html Our episode on BUFFERS https://postgres.fm/episodes/buffers-by-default Our episode on TOAST https://postgres.fm/episodes/toast Our episode on index maintenance https://postgres.fm/episodes/index-maintenance Chelsea's website: https://chelseadole.com/~~~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!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith special thanks to:Jessie Draws for the amazing artwork 

Michael is joined by Jonathan Katz, PostgreSQL Core Team member, Principle Product Manager at AWS, and also pgvector contributor, to discuss pgvector. They cover what it is, why it's so popular all of a sudden, some tuning and tradeoff guidance, and a look to the future. Here are some links to things they mentioned:pgvector https://github.com/pgvector/pgvectorOur episode on companion databases https://postgres.fm/episodes/companion-databasesVectors are the new JSON (talk by Jonathan) https://www.youtube.com/watch?v=D_1zunKblAUpgvector 0.5.0 feature highlights and howtos (blog post by Jonathan) https://jkatz05.com/post/postgres/pgvector-overview-0.5.0HNSW indexing and searching (blog post by Jonathan) https://aws.amazon.com/blogs/database/accelerate-hnsw-indexing-and-searching-with-pgvector-on-amazon-aurora-postgresql-compatible-edition-and-amazon-rds-for-postgresqlOur episode on TOAST https://postgres.fm/episodes/toastpgvector changelog https://github.com/pgvector/pgvector/blob/master/CHANGELOG.mdHQANN paper https://arxiv.org/abs/2207.07940HNSW fast build branch https://github.com/pgvector/pgvector/tree/hnsw-fast-build pgconf.dev https://2024.pgconf.dev ~~~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!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith special thanks to:Jessie Draws for the amazing artwork 

Michael is joined by Alicja Kucharczyk, Program Manager for Azure Database for PostgreSQL at Microsoft and organiser of the Warsaw PostgreSQL User Group, to discuss Alicja's favorite tool: pgBadger. They cover what it is, how and when it's useful, and some guidance for getting the most out of it (without causing an outage). Here are some links to things they mentioned:pgBadger website https://pgbadger.darold.net pgBadger repo https://github.com/darold/pgbadgerAn example pgBadger report https://pgbadger.darold.net/examples/sample.html pg_stat_statements https://www.postgresql.org/docs/current/pgstatstatements.htmlAzure Guide https://techcommunity.microsoft.com/t5/azure-database-for-postgresql/how-to-generate-pgbadger-report-from-azure-database-for/ba-p/3756328Google Cloud SQL guide https://cloud.google.com/blog/products/databases/guide-to-the-database-observability-with-cloud-sqlRDS guide https://aws.amazon.com/blogs/database/optimizing-and-tuning-queries-in-amazon-rds-postgresql-based-on-native-and-external-tools/Community Insights on pgBadger (PGSQL Phriday Recap) https://techcommunity.microsoft.com/t5/azure-database-for-postgresql/community-insights-on-pgbadger-a-pgsql-phriday-010-recap/ba-p/3880911 PGSQL Phriday #010: Log analysis (blog post by Lætitia Avrot) https://mydbanotebook.org/post/log-analysis/ Nothing Compares To VACUUM/The Ballad of Bloat https://www.youtube.com/watch?v=2NxIngqq1y0 Explain Analyze (Feliz Navidad cover) https://www.youtube.com/watch?v=qznnzYZPdkM ~~~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!~~~Postgres FM is produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith special thanks to:Jessie Draws for the amazing artwork