Postgres FM Nikolay Samokhvalov and Michael Christofides

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) https://use-the-index-luke.com/no-offset LIMIT clause (docs) https://www.postgresql.org/docs/current/sql-select.html#SQL-LIMIT 
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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.aiMichael Christofides, founder of pgMustardWith special thanks to:
Jessie Draws for the amazing artwork 

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 https://www.depesz.com/2024/04/11/waiting-for-postgresql-17-invent-serialize-option-for-explain/ 
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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.aiMichael Christofides, founder of pgMustardWith special thanks to:
Jessie Draws for the amazing artwork 

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 https://postgres.fm/episodes/wal-and-checkpoint-tuningEgor Rogov’s book on Postgres Internals (chapter 10 on WAL) https://edu.postgrespro.com/postgresql_internals-14_en.pdf full_page_writes https://www.postgresql.org/docs/current/runtime-config-wal.html#GUC-FULL-PAGE-WRITES TRUNCATE https://www.postgresql.org/docs/current/sql-truncate.html Our episode on partitioning https://postgres.fm/episodes/partitioning Our episode on bloat https://postgres.fm/episodes/bloat Our episode on index maintenance https://postgres.fm/episodes/index-maintenance 
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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!
~~~
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 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 post by Sai) https://blog.peerdb.io/exploring-versions-of-the-postgres-logical-replication-protocol Logical Streaming Replication Protocol https://www.postgresql.org/docs/current/protocol-logical-replication.htmlREPLICA IDENTITY FULL https://www.postgresql.org/docs/current/sql-altertable.html#SQL-ALTERTABLE-REPLICA-IDENTITYOn the performance impact of REPLICA IDENTITY FULL in Postgres (blog post by Xata) https://xata.io/blog/replica-identity-full-performance max_slot_wal_keep_size https://www.postgresql.org/docs/current/runtime-config-replication.html#GUC-MAX-SLOT-WAL-KEEP-SIZE Active Active in Postgres 16 (blog post by Crunchy Data) https://www.crunchydata.com/blog/active-active-postgres-16 pgEdge https://www.pgedge.com/DistSQL (term used by Mark Callaghan) https://smalldatum.blogspot.com/2023/07/keeping-up-with-sql-dbms-market.html Five tips on Postgres logical decoding (blog post by Sai) https://blog.peerdb.io/five-tips-on-postgres-logical-decodingPG Slot Notify: Monitor Postgres Slot Growth in Slack (blog post by PeerDB) https://blog.peerdb.io/pg-slot-notify-monitor-postgres-slot-growth-in-slack
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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!
~~~
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 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) https://github.com/postgres-ai/postgres-howtos/blob/main/0016_how_to_get_into_trouble_using_some_postgres_features.mdDon’t do this (jOOQ list) http://www.jooq.org/doc/3.19/manual/reference/dont-do-thisDon’t use NOT IN (jOOQ) https://www.jooq.org/doc/3.19/manual/reference/dont-do-this/dont-do-this-sql-not-in/ Our episode about NULLs https://postgres.fm/episodes/nulls-the-good-the-bad-the-ugly-and-the-unknown Our episode on timestamps https://postgres.fm/episodes/timestamps
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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!
~~~
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 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 https://postgres.fm/episodes/companion-databasespgvector episode https://postgres.fm/episodes/pgvectorFull Text Search https://www.postgresql.org/docs/current/textsearch.htmlSemantic search https://en.wikipedia.org/wiki/Semantic_searchFaceted search https://en.wikipedia.org/wiki/Faceted_searchFaceting large result sets in PostgreSQL https://www.cybertec-postgresql.com/en/faceting-large-result-sets/RUM index https://github.com/postgrespro/rum Hybrid search (Supabase guide) https://supabase.com/docs/guides/ai/hybrid-search Elastic https://www.elastic.co/ GiST indexes https://www.postgresql.org/docs/current/gist.html GIN indexes https://www.postgresql.org/docs/current/gin.html btree_gist https://www.postgresql.org/docs/current/btree-gist.html btree_gin https://www.postgresql.org/docs/current/btree-gin.html pg_trgrm https://www.postgresql.org/docs/current/pgtrgm.html Text Search Types (tsvector and tsquery) https://www.postgresql.org/docs/current/datatype-textsearch.html Postgres full text search with the “websearch” syntax (blog post by Adam Johnson) https://adamj.eu/tech/2024/01/03/postgresql-full-text-search-websearch/Understanding Postgres GIN Indexes: The Good and the Bad (blog post by Lukas Fittl) https://pganalyze.com/blog/gin-index ParadeDB https://www.paradedb.com/ ZomboDB https://www.zombodb.com/ Introduction to Information Retrieval (book by Manning, Raghavan, and Schütze) https://www.amazon.co.uk/Introduction-Information-Retrieval-Christopher-Manning/dp/0521865719 How to build a search engine with Ruby on Rails (blog post by Justin Searls) https://blog.testdouble.com/posts/2021-09-09-how-to-build-a-search-engine-with-ruby-on-rails/
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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!
~~~
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