Nikolay and Michael discuss Postgres minor releases — how the schedule works, options for upgrading to them, and the importance of reading the release notes. Here are some links to things they mentioned: PostgreSQL 16.3, 15.7, 14.12, 13.15, and 12.19 released (announcement) https://www.postgresql.org/about/news/postgresql-163-157-1412-1315-and-1219-released-2858/ PostgreSQL versioning policy https://www.postgresql.org/support/versioning/ PostgreSQL 14.4 release notes (most recent minor...

Nikolay and Michael discuss custom and generic planning in prepared statements — how it works, how issues can present themselves, some ways to view the generic plan, and some benefits of avoiding planning (not just time).  Here are some links to things they mentioned: PREPARE https://www.postgresql.org/docs/current/sql-prepare.html track_activity_query_size https://www.postgresql.org/docs/current/runtime-config-statistics.html#GUC-TRACK-ACTIVITY-QUERY-SIZE plan_cache_mode...

Nikolay and Michael discuss LIMIT in Postgres — what it does, how it can help with performance, and an interesting example where adding it can actually hurt performance(!) Here are some links to things they mentioned: LIMIT considered harmful in PostgreSQL (Twitter thread by Christophe Pettus) https://twitter.com/Xof/status/1413542818673577987 LIMIT and OFFSET (docs) https://www.postgresql.org/docs/current/queries-limit.html No OFFSET (by Markus Winand)...

Nikolay and Michael return to the topic of using the buffers explain parameter — with a new analogy, some (conspiracy) theories of why it's still not on by default, and some related chat about the serialize parameter coming in 17. Here are some links to things they mentioned: BUFFERS by default (episode 4) https://postgres.fm/episodes/buffers-by-default Lightning talk by Michael at pgDay Paris (5 mins) https://www.youtube.com/watch?v=WfY-mSpUzaQ&t=1470s Waiting for SERIALIZE...

Nikolay and Michael discuss doing massive DELETE operations in Postgres — what can go wrong, how to prevent major issues, and some ideas to minimise their impact. Here are some links to things they mentioned: Article based on Nikolay’s talk, including batching implementation (translated to English) https://habr-com.translate.goog/en/articles/523536/?_x_tr_sl=ru&_x_tr_tl=en&_x_tr_hist=true Our episode on WAL and checkpoint tuning...

Nikolay and Michael are joined by Sai Srirampur, CEO and Co-founder of PeerDB, to discuss how to overcome several logical replication issues. They discuss the protocol versions, minimising slot growth, minimising lag, and some tips and tricks for scaling things well. Here are some links to things they mentioned: PeerDB https://www.peerdb.io/Our episode on logical replication https://postgres.fm/episodes/logical-replicationExploring versions of the Postgres logical replication protocol (blog...

Nikolay and Michael discuss several "Don't do this" lists about Postgres — picking out their favourite items, as well as some contentious ones that could be clearer, or not included.  Here are some links to things they mentioned: Don’t do this (PostgreSQL wiki page) https://wiki.postgresql.org/wiki/Don't_Do_ThisHow to get into trouble using some Postgres features (how to by Nikolay)...

Nikolay and Michael have a high-level discussion on all things search — touching on full-text search, semantic search, and faceted search. They discuss what comes in Postgres core, what is possible via extensions, and some thoughts on performance vs implementation complexity vs user experience.  Here are some links to things they mentioned: Simon Riggs https://www.linkedin.com/feed/update/urn:li:activity:7178702287740022784/Companion databases episode...

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...

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)...

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:...

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...

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...

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...

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)...

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...

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)...

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...

With Nikolay taking a well-earned break, Michael covers the basics of EXPLAIN — what it is, the parameters available, and a process he recommends for using it. Here are some links to the things mentioned: EXPLAIN (docs) https://www.postgresql.org/docs/current/sql-explain.htmlUsing EXPLAIN (docs) https://www.postgresql.org/docs/current/using-explain.htmlEXPLAIN Explained (talk by Josh Berkus https://www.youtube.com/watch?app=desktop&v=mCwwFAl1pBUBeyond joins and indexes (slides from talk...

Happy holidays! Today's topic is work_mem — how it's used and how to tune it. Related post: https://x.com/samokhvalov/status/1740813478150189172?s=46&t=HSxrW86NZqzPQP9vXVJEWg.

Nikolay and Michael discuss partitioning by ULID — revisiting some of the old UUID vs bigint key debate in light of some new UUID specs, and how these can be used for partitioning (by time).  Here are some links to things they mentioned: Nikolay’s episode on UUID (for primary keys) https://postgres.fm/episodes/uuid Postgres TV hacking session with Andrey and Kirk: https://www.youtube.com/watch?v=YPq_hiOE-N8UUIDv7 patch https://commitfest.postgresql.org/43/4388/ Use ULID Idempotency Keys (tip...

Nikolay and Michael discuss hash indexes in Postgres — what they are, some brief history, their pros and cons vs btrees, and whether or when they recommend using them. Update: the idea Nikolay mentioned at the end of this episode turns out to be a little fraught (and as such, inadvisable).  Here are some links to things they mentioned: Index types (docs) https://www.postgresql.org/docs/current/indexes-types.html  Re-introducing hash indexes in PostgreSQL (blog post by Haki Benita and Michael)...

Nikolay and Michael discuss PostgreSQL constraints — the six different types we have, how to add and modify them, including on large tables with high TPS.  Here are some links to things they mentioned: Constraints (docs) https://www.postgresql.org/docs/current/ddl-constraints.htmlUnique index vs unique constraint issue (2017) https://www.postgresql.org/message-id/flat/CANNMO%2B%2B7%2BuVMj%2BZPGKB_zuRpKE0sNthy2Z-_oKSS%3DoE3_rN7QA%40mail.gmail.com Our episode on NULLs...

Nikolay and Michael discuss PostgreSQL events — whether in-person or online, large conferences or small meet-ups, as well as some strong opinions based on their experiences attending, speaking, and organising them.  Here are some links to things they mentioned: PGSQL Phriday #014: PostgreSQL Events https://www.cybertec-postgresql.com/en/pgsql-phriday-014-postgresql-events/  PGCon https://www.pgcon.org/  Highload https://highload.rs/  The San Francisco Bay Area PostgreSQL Meetup Group...