Nikolay and Michael discuss a couple of surprising ways read queries (selects) can cause writes (shared buffers dirtied) in Postgres. Here are some links to things they mentioned:Reads causing writes in Postgres (post by Alex Jesipow) https://jesipow.com/blog/postgres-reads-cause-writes/Exploring how SELECT queries can produce disk writes (post by Nikolay Sivko) https://blog.okmeter.io/postgresql-exploring-how-select-queries-can-produce-disk-writes-f36c8bee6b6f Hint Bits (wiki) https://wiki.postgresql.org/wiki/Hint_Bitspg_stat_statements https://www.postgresql.org/docs/current/pgstatstatements.html pg_stat_kcache https://github.com/powa-team/pg_stat_kcache pg_wait_sampling https://github.com/postgrespro/pg_wait_sampling BUFFERS by default (episode 4!) https://postgres.fm/episodes/buffers-by-default Page layout (docs) https://www.postgresql.org/docs/current/storage-page-layout.html From Reddit (user merlinm), PD_ALL_VISIBLE may be a third case https://www.reddit.com/r/PostgreSQL/comments/1hjuyfn/comment/m3e6e7v/ Coroot https://coroot.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
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26:48
NOT VALID constraints
Nikolay and Michael discuss adding constraints in an online fashion, using NOT VALID and then VALIDATE CONSTRAINT. Here are some links to things they mentioned:ADD table_constraint NOT VALID https://www.postgresql.org/docs/current/sql-altertable.html#SQL-ALTERTABLE-DESC-ADD-TABLE-CONSTRAINTOur episode on zero-downtime migrations https://postgres.fm/episodes/zero-downtime-migrationsVALIDATE CONSTRAINT https://www.postgresql.org/docs/current/sql-altertable.html#SQL-ALTERTABLE-DESC-VALIDATE-CONSTRAINTALTER TABLE notes https://www.postgresql.org/docs/current/sql-altertable.html#SQL-ALTERTABLE-NOTESpgroll https://github.com/xataio/pgroll~~~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
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33:56
pg_squeeze
Michael and Nikolay are joined by Antonín Houska to discuss pg_squeeze — what it is, how it started, some of its features, and hopes of getting the functionality into core. Here are some links to things they mentioned:Antonín Houska https://postgres.fm/people/antonin-houskapg_squeeze https://github.com/cybertec-postgresql/pg_squeezeCybertec https://www.cybertec-postgresql.compg_repack https://github.com/reorg/pg_repackIntroducing pg_squeeze (by Kaarel Moppel) https://www.cybertec-postgresql.com/en/introducing-pg_squeeze-a-postgresql-extension-to-auto-rebuild-bloated-tablespg_squeeze is included in the PostgreSQL APT packages https://wiki.postgresql.org/wiki/Aptpg_squeeze is included in the PostgreSQL Yum packages https://yum.postgresql.orgpg_rewrite https://github.com/cybertec-postgresql/pg_rewriteVACUUM FULL / CLUSTER CONCURRENTLY patch https://commitfest.postgresql.org/51/5117~~~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
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36:26
pg_duckdb
Michael and Nikolay are joined by Joe Sciarrino and Jelte Fennema-Nio to discuss pg_duckdb — what it is, how it started, what early users are using it for, and what they're working on next. Here are some links to things they mentioned:Joe Sciarrino https://postgres.fm/people/joe-sciarrinoJelte Fennema-Nio https://postgres.fm/people/jelte-fennema-niopg_duckdb https://github.com/duckdb/pg_duckdbHydra https://www.hydra.soMotherDuck https://motherduck.comThe problems and benefits of an elephant with a beak (lightning talk by Jelte) https://www.youtube.com/watch?v=ogvbKE4fw9A&list=PLF36ND7b_WU4QL6bA28NrzBOevqUYiPYq&t=1073spg_duckdb announcement post (by Jordan and Brett from MotherDuck) https://motherduck.com/blog/pg_duckdb-postgresql-extension-for-duckdb-motherduckpg_duckdb 0.2 release https://github.com/duckdb/pg_duckdb/releases/tag/v0.2.0~~~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
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40:08
RLS vs performance
Nikolay and Michael discuss Row Level Security in Postgres, focussing on the performance side effects and some tips to avoid (or minimize) them. Here are some links to things they mentioned:Row Security Policies (docs) https://www.postgresql.org/docs/current/ddl-rowsecurity.html7+ million Postgres tables (recent talk by Kailash Nadh) https://www.youtube.com/watch?v=xhi5Q_wL9i0Row Level Security guide (Supabase docs) https://supabase.com/docs/guides/database/postgres/row-level-securitycurrent_setting function https://www.postgresql.org/docs/current/functions-admin.html#id-1.5.8.34.3.6.2.2.1.1.1.1Our slow count episode https://postgres.fm/episodes/slow-countRLS Performance and Best Practices (gist from Gary Austin) https://github.com/orgs/supabase/discussions/14576Everything you need to know about Postgres Row Level Security (talk by Paul Copplestone) https://www.youtube.com/watch?v=vZT1Qx2xUCoBUFFERS enabled for EXPLAIN ANALYZE by default (commit for Postgres 18) https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=c2a4078ebad71999dd451ae7d4358be3c9290b07Add UUID version 7 generation function (commit for Postgres 18) https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=78c5e141e9c139fc2ff36a220334e4aa25e1b0ebPostgres hacking session with Andrey and Kirk (for UUIDv7): https://www.youtube.com/watch?v=YPq_hiOE-N8~~~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
Sverige