Postgres FM

Nik and Michael discuss the various changes to EXPLAIN that arrived in Postgres 18. Here are some links to things they mentioned: EXPLAIN (official docs) https://www.postgresql.org/docs/current/sql-explain.htmlUsing EXPLAIN (official docs) https://www.postgresql.org/docs/current/using-explain.html EXPLAIN glossary (pgMustard site) https://www.pgmustard.com/docs/explainPostgres 18 release notes https://www.postgresql.org/docs/release/18.0/Enable BUFFERS with EXPLAIN ANALYZE by default (commit) https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=c2a4078ebOur (first) BUFFERS by default episode https://postgres.fm/episodes/buffers-by-default Show index search count in EXPLAIN ANALYZE (commit) https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=0fbceae841cb5a31b13d3f284ac8fdd19822ecebOur episode on Skip scan with Peter Geoghegan https://postgres.fm/episodes/skip-scanWhat do the new Index Searches lines in EXPLAIN mean? https://www.pgmustard.com/blog/what-do-index-searches-in-explain-meanpg_stat_plans presentation by Lukas Fittl https://www.youtube.com/watch?v=26coQV3f-wkImprove EXPLAIN's display of window functions (commit) https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=8b1b34254Show Parallel Bitmap Heap Scan worker stats in EXPLAIN ANALYZE (commit) https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=5a1e6df3bAdd information about WAL buffers being full (commit) https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=320545bfc ~~~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 credit to:Jessie Draws for the elephant artwork

Nik talks Michael through a recent benchmark he worked with Maxim Boguk on, to see how quickly they could provision a replica. Here are some links to things they mentioned:Ultra-fast replica creation with pgBackRest (blog post by Maxim Boguk and Nik) https://postgres.ai/blog/20251105-postgres-marathon-2-012-ultra-fast-replica-creation-pgbackrestCopying a database episode https://postgres.fm/episodes/copying-a-databaseAdd snapshot backup support for PostgreSQL in wal-g (draft PR by Andrey Borodin) https://github.com/wal-g/wal-g/pull/2101Multi-threaded pg_basebackup discussion 1: https://www.postgresql.org/message-id/flat/CAEHH7R4%3D_GN%2BLSsj0YZOXZ13yc%3DGk9umJOLNopjS%3DimK0c1mWA%40mail.gmail.comMulti-threaded pg_basebackup discussion 2: https://www.postgresql.org/message-id/flat/io_method https://www.postgresql.org/docs/current/runtime-config-resource.html#GUC-IO-METHOD pgBackRest https://github.com/pgbackrest/pgbackrestAdd sequence synchronization for logical replication (commit) https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=5509055d6956745532e65ab218e15b99d87d66ce Allow process priority to be set (pgBackRest feature added by David Steele) https://github.com/pgbackrest/pgbackrest/pull/2693 Hard limit on process-max (pgBackRest issue from 2019) https://github.com/pgbackrest/pgbackrest/issues/696 ~~~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 credit to:Jessie Draws for the elephant artwork

Nik and Michael discuss the concept of gapless sequences — when you might want one, why sequences in Postgres can have gaps, and an idea or two if you do want them.And one quick clarification: changing the CACHE option in CREATE SEQUENCE can lead to even more gaps, the docs mention it explicitly. Here are some links to things they mentioned:CREATE SEQUENCE https://www.postgresql.org/docs/current/sql-createsequence.htmlSequence Manipulation Functions https://www.postgresql.org/docs/current/functions-sequence.htmlOne, Two, Skip a Few (post by Pete Hamilton from Incident io) https://incident.io/blog/one-two-skip-a-fewPostgres sequences can commit out-of-order (blog post by Anthony Accomazzo / Sequin) https://blog.sequinstream.com/postgres-sequences-can-commit-out-of-orderLogical Replication of sequences (hackers thread) https://www.postgresql.org/message-id/flat/CAA4eK1LC%2BKJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ%40mail.gmail.comSynchronization of sequences to subscriber (patch entry in commitfest) https://commitfest.postgresql.org/patch/5111/Get or Create (episode with Haki Benita) https://postgres.fm/episodes/get-or-createGerman tank problem https://en.wikipedia.org/wiki/German_tank_problem~~~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 credit to:Jessie Draws for the elephant artwork

Nik and Michael discuss lightweight locks in Postgres — how they differ to (heavier) locks, some occasions they can be troublesome, and some resources for working out what to do if you hit issues. Here are some links to things they mentioned:Wait Events of Type LWLock https://www.postgresql.org/docs/current/monitoring-stats.html#WAIT-EVENT-LWLOCK-TABLEOur episode on (heavier) locks https://postgres.fm/episodes/locksNik’s new marathon posts https://postgres.ai/blog/tags/postgres-marathonPostgres LISTEN/NOTIFY does not scale (blog post by Recall ai) https://www.recall.ai/blog/postgres-listen-notify-does-not-scaleExplicit Locking https://www.postgresql.org/docs/current/explicit-locking.htmlpg_stat_activity https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-PG-STAT-ACTIVITY-VIEWTuning with wait events for RDS for PostgreSQL https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/PostgreSQL.Tuning.htmlMultiXact member exhaustion incidents (blog post by Cosmo Wolfe / Metronome) https://metronome.com/blog/root-cause-analysis-postgresql-multixact-member-exhaustion-incidents-may-2025pg_index_pilot https://gitlab.com/postgres-ai/pg_index_pilotMyths and Truths about Synchronous Replication in PostgreSQL (talk by Alexander Kukushkin) https://www.youtube.com/watch?v=PFn9qRGzTMcPostgres Indexes, Partitioning and LWLock:LockManager Scalability (blog post by Jeremy Schneider) https://ardentperf.com /2024/03/03/postgres-indexes-partitioning-and-lwlocklockmanager-scalability~~~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 credit to:Jessie Draws for the elephant artwork

Nik and Michael discuss user management in Postgres — how roles work, making administration easier, setting passwords, and avoiding them being logged. Here are some links to things they mentioned:Roles https://www.postgresql.org/docs/current/user-manag.html Privileges https://www.postgresql.org/docs/current/ddl-priv.htmlALTER DEFAULT PRIVILEGES https://www.postgresql.org/docs/current/sql-alterdefaultprivileges.htmlGRANT https://www.postgresql.org/docs/current/sql-grant.htmlREASSIGN OWNED https://www.postgresql.org/docs/current/sql-reassign-owned.htmlALTER ROLE (including SET) https://www.postgresql.org/docs/current/sql-alterrole.html CREATE ROLE https://www.postgresql.org/docs/current/sql-createrole.htmlHave I Been Pwned https://haveibeenpwned.comPwned Passwords API https://haveibeenpwned.com/API/v3#PwnedPasswordsCrunchy Data PostgreSQL Security Technical Implementation Guide (STIG) https://www.crunchydata.com/blog/announcing-the-crunchy-data-postgresql-stigOur episode on auditing https://postgres.fm/episodes/auditing~~~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 credit to:Jessie Draws for the elephant artwork

Nik and Michael discuss the newly released Postgres 18 — the bigger things it includes, some of their personal highlights, and some thoughts towards the future. Here are some links to things they mentioned:Postgres 18 announcement https://www.postgresql.org/about/news/postgresql-18-released-3142Postgres 18 release notes https://www.postgresql.org/docs/18/release-18.htmlSkip scan episode with Peter Geoghegan https://postgres.fm/episodes/skip-scanEasier Postgres fine-tuning with online_advisor https://neon.com/blog/easier-postgres-fine-tuning-with-online_advisorpganalyze Index Advisor https://pganalyze.com/index-advisorBUFFERS by default https://postgres.fm/episodes/buffers-by-defaultBuffers II (the sequel) https://postgres.fm/episodes/buffers-ii-the-sequelReturn of the BUFFERS https://postgres.fm/episodes/return-of-the-buffersUUID https://postgres.fm/episodes/uuidPartitioning by ULID https://postgres.fm/episodes/partitioning-by-uliduuidv7 and uuid_extract_timestamp functions https://www.postgresql.org/docs/current/functions-uuid.htmlAdd --no-policies option to pg_dump, pg_dumpall, and pg_restore https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=cd3c45125Add ONLY support for VACUUM and ANALYZE https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=62ddf7ee9Make "vacuumdb --analyze-only" process partitioned tables (committed recently for Postgres 19) https://commitfest.postgresql.org/patch/5871/NOT VALID constraints https://postgres.fm/episodes/not-valid-constraintsThe year of the Lock Manager’s Revenge (post by Jeremy Schneider) https://ardentperf.com/2024/03/03/postgres-indexes-partitioning-and-lwlocklockmanager-scalabilityIncrease the number of fast-path lock slots https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=c4d5cb71d"enable" parameters will work differently in Postgres 18 https://www.pgmustard.com/blog/enable-parameters-work-differently-in-postgres-18logerrors https://github.com/munakoiso/logerrors~~~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 credit to:Jessie Draws for the elephant artwork

Nik and Michael are joined by Harry Brundage from Gadget to talk about their recent zero-downtime major version upgrade, how they use Postgres more generally, their dream database, and some challenges of providing Postgres as an abstracted service at scale. Here are some links to things they mentioned:Harry Brundage https://postgres.fm/people/harry-brundageGadget https://gadget.devZero downtime Postgres upgrades using logical replication (blog post) https://gadget.dev/blog/zero-downtime-postgres-upgrades-using-logical-replicationHOT updates https://www.postgresql.org/docs/current/storage-hot.htmlPgDog https://pgdog.devMultigres https://multigres.comNeki https://www.neki.devRunning 10 Million PostgreSQL Indexes In Production (Heap blog post) https://www.heap.io/blog/running-10-million-postgresql-indexes-in-productionpgwatch2 (Postgres.ai Edition) https://gitlab.com/postgres-ai/pgwatch2Advanced query insights on AlloyDB https://cloud.google.com/alloydb/docs/advanced-query-insights-overviewOrioleDB https://www.orioledb.comNot discussed but relevant: Gadget have also now published a blog post about their sharding! https://gadget.dev/blog/sharding-our-core-postgres-database-without-any-downtime~~~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 credit to:Jessie Draws for the elephant artwork

Nik and Michael are joined by Simon Eskildsen from turbopuffer — among other things, they discuss ANN index types, tradeoffs that can make sense for search workloads, and when it can make sense to move search out of Postgres. Here are some links to things they mentioned:Simon Eskildsen https://postgres.fm/people/simon-eskildsenturbopuffer https://turbopuffer.comUse ULID Idempotency Keys (tip 6 in this blog post from Shopify) https://shopify.engineering/building-resilient-payment-systemsPostgreSQL 18 Release Candidate 1 https://www.postgresql.org/about/news/postgresql-18-rc-1-released-3130Understanding DiskANN (blog post by Junaid Ahmed) https://www.tigerdata.com/blog/understanding-diskannSPFresh: Incremental In-Place Update for Billion-Scale Vector Search (paper) https://arxiv.org/abs/2410.14452Amazon S3 adds new functionality for conditional writes https://aws.amazon.com/about-aws/whats-new/2024/11/amazon-s3-functionality-conditional-writesAmazon S3 Vectors https://aws.amazon.com/s3/features/vectors~~~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 credit to:Jessie Draws for the elephant artwork

Nik and Michael discuss when not to use Postgres — specifically use cases where it still makes sense to store data in another system. Here are some links to things they mentioned:Just use Postgres (blog post by Ethan McCue) https://mccue.dev/pages/8-16-24-just-use-postgresJust Use Postgres for Everything (blog post by Stephan Schmidt) https://www.amazingcto.com/postgres-for-everythingReal-time analytics episode https://postgres.fm/episodes/real-time-analyticsCrunchy Data Joins Snowflake https://www.crunchydata.com/blog/crunchy-data-joins-snowflakeTwo sizes fit most: PostgreSQL and Clickhouse (blog post by Sid Sijbrandij) https://about.gitlab.com/blog/two-sizes-fit-most-postgresql-and-clickhousepg_duckdb episode https://postgres.fm/episodes/pg_duckdbCloudberry https://github.com/apache/cloudberryTime-series considerations episode https://postgres.fm/episodes/time-series-considerationsQueues in Postgres episode https://postgres.fm/episodes/queues-in-postgresLarge Objects https://www.postgresql.org/docs/current/largeobjects.html PGlite https://pglite.devParadeDB https://www.paradedb.comZomboDB https://github.com/zombodb/zombodbturbopuffer https://turbopuffer.comHNSW vs. DiskANN (blog post by Haziqa Sajid) https://www.tigerdata.com/learn/hnsw-vs-diskannSPANN: Highly-efficient Billion-scale Approximate Nearest Neighbor Search (paper) https://www.microsoft.com/en-us/research/wp-content/uploads/2021/11/SPANN_finalversion1.pdfAmazon S3 Vectors https://aws.amazon.com/s3/features/vectorsIterative Index Scans added to pgvector in 0.8.0 https://github.com/pgvector/pgvector/issues/678S3 FDW from Supabase https://github.com/supabase/wrappers/tree/main/wrappers/src/fdw/s3_fdw~~~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 credit to:Jessie Draws for the elephant artwork

Nik and Michael discuss disks in relation to Postgres — why they matter, how saturation can happen, some modern nuances, and how to prepare to avoid issues. Here are some links to things they mentioned:Nik’s tweet demonstrating a NOTIFY hot spot https://x.com/samokhvalov/status/1959468091035009245Postgres LISTEN/NOTIFY does not scale (blog post by Recall ai) https://www.recall.ai/blog/postgres-listen-notify-does-not-scaletrack_io_timing https://www.postgresql.org/docs/current/runtime-config-statistics.html#GUC-TRACK-IO-TIMINGpg_test_timing https://www.postgresql.org/docs/current/pgtesttiming.html PlanetScale for Postgres https://planetscale.com/blog/planetscale-for-postgresOut of disk episode https://postgres.fm/episodes/out-of-disk100TB episode https://postgres.fm/episodes/to-100tb-and-beyond Latency Numbers Every Programmer Should Know https://gist.github.com/jboner/2841832Fio https://github.com/axboe/fio~~~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 credit to:Jessie Draws for the elephant artwork

Nik and Michael discuss multi-column indexes in Postgres — what they are, how to think about them, and some guidance around using them effectively. Here are some links to things they mentioned:Multicolumn Indexes (docs) https://www.postgresql.org/docs/current/indexes-multicolumn.htmlOur episode on Index-only scans https://postgres.fm/episodes/index-only-scansCombining Multiple Indexes (docs) https://www.postgresql.org/docs/current/indexes-bitmap-scans.htmlEnable BUFFERS with EXPLAIN ANALYZE by default https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=c2a4078ebad71999dd451ae7d4358be3c9290b07“PostgreSQL includes an implementation of the standard btree […] The only limitation is that an index entry cannot exceed approximately one-third of a page” https://www.postgresql.org/docs/current/btree.htmlOur episode on HOT updates https://postgres.fm/episodes/hot-updatesOur episode on LIMIT vs Performance https://postgres.fm/episodes/limit-vs-performance~~~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 credit to:Jessie Draws for the elephant artwork

Nikolay and Michael discuss self-driving Postgres — what it could mean, using self-driving cars as a reference, and ideas for things to build and optimize for in this area. Here are some links to things they mentioned:Nikolay’s blog post on Self-driving Postgres https://postgres.ai/blog/20250725-self-driving-postgresSAE J3016 levels of driving automation https://www.sae.org/news/2019/01/sae-updates-j3016-automated-driving-graphicOracle Autonomous Database https://www.oracle.com/uk/autonomous-database/Self-Driving Database Management Systems (2017 paper) https://db.cs.cmu.edu/papers/2017/p42-pavlo-cidr17.pdfPGTune https://pgtune.leopard.in.ua/pg_index_pilot https://gitlab.com/postgres-ai/pg_index_pilot/[Vibe] Hacking Postgres with Andrey, Kirk, Nik – index bloat, btree page merge https://www.youtube.com/watch?v=D1PEdDcvZTw~~~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 credit to:Jessie Draws for the elephant artwork

Nikolay and Michael discuss case-insensitive data — when we want to treat columns as case-insensitive, and the pros and cons of using citext, functions like lower(), or a custom collation. Here are some links to things they mentioned:citext https://www.postgresql.org/docs/current/citext.htmlOur episode on over-indexing https://postgres.fm/episodes/over-indexingNondeterministic collations https://www.postgresql.org/docs/current/collation.html#COLLATION-NONDETERMINISTICHow to migrate from Django’s PostgreSQL CI Fields to use a case-insensitive collation (blog post by Adam Johnson) https://adamj.eu/tech/2023/02/23/migrate-django-postgresql-ci-fields-case-insensitive-collationThe collation versioning problem with ICU 73 (blog post by Daniel Vérité) https://postgresql.verite.pro/blog/2023/10/20/icu-73-versioning.htmlamcheck https://www.postgresql.org/docs/current/amcheck.html~~~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 credit to:Jessie Draws for the elephant artwork

Nikolay talks to Michael about Postgres AI's new monitoring tool — what it is, how its different to other tools, and some of the thinking behind it. Here are some links to things they mentioned:postgres_ai monitoring https://gitlab.com/postgres-ai/postgres_aiDB Lab 4.0 announcement https://github.com/postgres-ai/database-lab-engine/releases/tag/v4.0.0pganalyze https://pganalyze.compostgres-checkup https://gitlab.com/postgres-ai/postgres-checkupPercona Monitoring and Management (PMM) https://github.com/percona/pmmpgwatch https://github.com/cybertec-postgresql/pgwatchpgwatch Postgres AI Edition https://gitlab.com/postgres-ai/pgwatch2libpg_query https://github.com/pganalyze/libpg_queryThe Four Golden Signals https://sre.google/sre-book/monitoring-distributed-systems/#xref_monitoring_golden-signalslogerrors https://github.com/munakoiso/logerrors~~~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 credit to:Jessie Draws for the elephant artwork

Nikolay and Michael are joined by Andrew Johnson and Nate Brennand from Metronome to discuss MultiXact member space exhaustion — what it is, how they managed to hit it, and some tips to prevent running into it at scale. Here are some links to things they mentioned:Nate Brennand https://postgres.fm/people/nate-brennandAndrew Johnson https://postgres.fm/people/andrew-johnsonMetronome https://metronome.comRoot Cause Analysis: PostgreSQL MultiXact member exhaustion incidents (blog post by Metronome) https://metronome.com/blog/root-cause-analysis-postgresql-multixact-member-exhaustion-incidents-may-2025Multixacts and Wraparound (docs) https://www.postgresql.org/docs/current/routine-vacuuming.html#VACUUM-FOR-MULTIXACT-WRAPAROUNDmultixact.c source code https://github.com/postgres/postgres/blob/master/src/backend/access/transam/multixact.cAdd pg_stat_multixact view for multixact membership usage monitoring (patch proposal by Andrew, needing review!) https://commitfest.postgresql.org/patch/5869/PostgreSQL subtransactions considered harmful (blog post by Nikolay) https://postgres.ai/blog/20210831-postgresql-subtransactions-considered-harmfulvacuum_multixact_failsafe_age doesn't account for MultiXact member exhaustion (thread started by Peter Geoghegan) https://www.postgresql.org/message-id/flat/CAH2-WzmLPWJk3gbAxy8dHY%2BA-Juz_6uGwfe6DkE8B5-dTDvLcw%40mail.gmail.comAmazon S3 Vectors https://aws.amazon.com/blogs/aws/introducing-amazon-s3-vectors-first-cloud-storage-with-native-vector-support-at-scale/MultiXacts in PostgreSQL: usage, side effects, and monitoring (blog post by Shawn McCoy and Divya Sharma from AWS) https://aws.amazon.com/blogs/database/multixacts-in-postgresql-usage-side-effects-and-monitoring/Postgres Aurora multixact monitoring queries https://gist.github.com/natebrennand/0924f723ff61fa897c4106379fc7f3dc And finally an apology and a correction, the membership space is ~4B, not ~2B as said by Michael in the episode! Definition here:https://github.com/postgres/postgres/blob/f6ffbeda00e08c4c8ac8cf72173f84157491bfde/src/include/access/multixact.h#L31And here's the formula discussed for calculating how the member space can grow quadratically by the number of overlapping transactions:Members can be calculated via: aₙ = 2 + [sum from k=3 to n+1 of k]This simplifies to: aₙ = (((n+1)(n+2))/2) - 1~~~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 are joined by Sugu Sougoumarane to discuss Multigres — a project he's joined Supabase to lead, building an adaptation of Vitess for Postgres! Here are some links to things they mentioned:Sugu Sougoumarane https://postgres.fm/people/sugu-sougoumaraneSupabase https://supabase.comAnnouncing Multigres https://supabase.com/blog/multigres-vitess-for-postgresVitess https://github.com/vitessio/vitessSPQR https://github.com/pg-sharding/spqrCitus https://github.com/citusdata/citusPgDog https://github.com/pgdogdev/pgdogMyths and Truths about Synchronous Replication in PostgreSQL (talk by Alexander Kukushkin) https://www.youtube.com/watch?v=PFn9qRGzTMcConsensus algorithms at scale (8 part series by Sugu) https://planetscale.com/blog/consensus-algorithms-at-scale-part-1A More Flexible Paxos (blog post by Sugu) https://www.sougou.io/a-more-flexible-paxoslibpg_query https://github.com/pganalyze/libpg_queryPL/Proxy https://github.com/plproxy/plproxyPlanetScale Postgres Benchmarking https://planetscale.com/blog/benchmarking-postgresMultiXact member exhaustion incidents (blog post by Cosmo Wolfe / Metronome) https://metronome.com/blog/root-cause-analysis-postgresql-multixact-member-exhaustion-incidents-may-2025~~~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 are joined by Gwen Shapira to discuss multi-tenant architectures — the high level options, the pros and cons of each, and how they're trying to help with Nile. Here are some links to things they mentioned:Gwen Shapira https://postgres.fm/people/gwen-shapiraNile https://www.thenile.devSaaS Tenant Isolation Strategies (AWS whitepaper) https://docs.aws.amazon.com/whitepapers/latest/saas-tenant-isolation-strategies/saas-tenant-isolation-strategies.html Row Level Security https://www.postgresql.org/docs/current/ddl-rowsecurity.htmlCitus https://github.com/citusdata/citusPostgres.AI Bot https://postgres.ai/blog/20240127-postgres-ai-bot RLS Performance and Best Practices https://supabase.com/docs/guides/troubleshooting/rls-performance-and-best-practices-Z5JjwvCase Gwen mentioned about the planner thinking an optimisation was unsafe Re-engineering Postgres for Millions of Tenants (Gwen’s recent talk at PGConf.dev) https://www.youtube.com/watch?v=EfAStGb4s88 Multi-tenant database the good, the bad, the ugly (talk by Pierre Ducroquet at PgDay Paris) https://www.youtube.com/watch?v=4uxuPfSvTGU ~~~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 looking at queries by mean time — when it makes sense, why ordering by a percentile (like p99) might be better, and the merits of approximating percentiles in pg_stat_statements using the standard deviation column. Here are some links to things they mentioned:Approximate the p99 of a query with pg_stat_statements (blog post by Michael) https://www.pgmustard.com/blog/approximate-the-p99-of-a-query-with-pgstatstatementspg_stat_statements https://www.postgresql.org/docs/current/pgstatstatements.html Our episode about track_planning https://postgres.fm/episodes/pg-stat-statements-track-planning pg_stat_monitor https://github.com/percona/pg_stat_monitorstatement_timeout https://www.postgresql.org/docs/current/runtime-config-client.html#GUC-STATEMENT-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 produced by:Michael Christofides, founder of pgMustardNikolay Samokhvalov, founder of Postgres.aiWith credit to:Jessie Draws for the elephant artwork

Nikolay and Michael discuss logging in Postgres — mostly what to log, and why changing quite a few settings can pay off big time in the long term. Here are some links to things they mentioned:What to log https://www.postgresql.org/docs/current/runtime-config-logging.html#RUNTIME-CONFIG-LOGGING-WHATOur episode about Auditing https://postgres.fm/episodes/auditing Our episode on auto_explain https://postgres.fm/episodes/auto_explain Here are the parameters they mentioned changing:log_checkpointslog_autovacuum_min_duration log_statementlog_connections and log_disconnectionslog_lock_waitslog_temp_fileslog_min_duration_statement log_min_duration_sample and log_statement_sample_rate And finally, some very useful tools they meant to mention but forgot to!   https://pgpedia.infohttps://postgresqlco.nfhttps://why-upgrade.depesz.com/show?from=16.9&to=17.5 ~~~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 credit to:Jessie Draws for the elephant artwork

Nikolay and Michael discuss moving off managed services — when and why you might want to, and some tips on how for very large databases. Here are some links to things they mentioned:Patroni https://github.com/patroni/patronipgBackRest https://github.com/pgbackrest/pgbackrestWAL-G https://github.com/wal-g/wal-gHetzner Cloud https://www.hetzner.com/cloudPostgres Extensions Day https://pgext.daypg_wait_sampling https://github.com/postgrespro/pg_wait_samplingpg_stat_kcache https://github.com/powa-team/pg_stat_kcacheauto_explain https://www.postgresql.org/docs/current/auto-explain.htmlFivetran https://www.fivetran.compgcopydb https://github.com/dimitri/pgcopydbKafka https://kafka.apache.orgDebezium https://debezium.iomax_slot_wal_keep_size https://www.postgresql.org/docs/current/runtime-config-replication.html#GUC-MAX-SLOT-WAL-KEEP-SIZElog_statement DDL https://www.postgresql.org/docs/current/runtime-config-logging.html#GUC-LOG-STATEMENTPgBouncer pause/resume https://www.pgbouncer.org/usage.html#pause-db~~~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 credit to:Jessie Draws for the elephant artwork