Postgres FM

Latest Episodes:

LWLocks Oct 17, 2025

Show notes

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-TABLE
Our episode on (heavier) locks https://postgres.fm/episodes/locks
Nik’s new marathon posts https://postgres.ai/blog/tags/postgres-marathon
Postgres LISTEN/NOTIFY does not scale (blog post by Recall ai) https://www.recall.ai/blog/postgres-listen-notify-does-not-scale
Explicit Locking https://www.postgresql.org/docs/current/explicit-locking.html
pg_stat_activity https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-PG-STAT-ACTIVITY-VIEW
Tuning with wait events for RDS for PostgreSQL https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/PostgreSQL.Tuning.html
MultiXact member exhaustion incidents (blog post by Cosmo Wolfe / Metronome) https://metronome.com/blog/root-cause-analysis-postgresql-multixact-member-exhaustion-incidents-may-2025
pg_index_pilot https://gitlab.com/postgres-ai/pg_index_pilot
Myths and Truths about Synchronous Replication in PostgreSQL (talk by Alexander Kukushkin) https://www.youtube.com/watch?v=PFn9qRGzTMc
Postgres Indexes, Partitioning and LWLock:LockManager Scalability (blog post by Jeremy Schneider) https://ardentperf.com /2024/03/03/postgres-indexes-partitioning-and-lwlocklockmanager-scalability

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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 produced by:

Michael Christofides, founder of pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

User management Oct 03, 2025

Show notes

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.html
ALTER DEFAULT PRIVILEGES https://www.postgresql.org/docs/current/sql-alterdefaultprivileges.html
GRANT https://www.postgresql.org/docs/current/sql-grant.html
REASSIGN OWNED https://www.postgresql.org/docs/current/sql-reassign-owned.html
ALTER ROLE (including SET) https://www.postgresql.org/docs/current/sql-alterrole.html
CREATE ROLE https://www.postgresql.org/docs/current/sql-createrole.html
Have I Been Pwned https://haveibeenpwned.com
Pwned Passwords API https://haveibeenpwned.com/API/v3#PwnedPasswords
Crunchy Data PostgreSQL Security Technical Implementation Guide (STIG) https://www.crunchydata.com/blog/announcing-the-crunchy-data-postgresql-stig
Our episode on auditing https://postgres.fm/episodes/auditing

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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 produced by:

Michael Christofides, founder of pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

Postgres 18 Sep 26, 2025

Show notes

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-3142
Postgres 18 release notes https://www.postgresql.org/docs/18/release-18.html
Skip scan episode with Peter Geoghegan https://postgres.fm/episodes/skip-scan
Easier Postgres fine-tuning with online_advisor https://neon.com/blog/easier-postgres-fine-tuning-with-online_advisor
pganalyze Index Advisor https://pganalyze.com/index-advisor
BUFFERS by default https://postgres.fm/episodes/buffers-by-default
Buffers II (the sequel) https://postgres.fm/episodes/buffers-ii-the-sequel
Return of the BUFFERS https://postgres.fm/episodes/return-of-the-buffers
UUID https://postgres.fm/episodes/uuid
Partitioning by ULID https://postgres.fm/episodes/partitioning-by-ulid
uuidv7 and uuid_extract_timestamp functions https://www.postgresql.org/docs/current/functions-uuid.html
Add --no-policies option to pg_dump, pg_dumpall, and pg_restore https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=cd3c45125
Add ONLY support for VACUUM and ANALYZE https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=62ddf7ee9
Make "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-constraints
The year of the Lock Manager’s Revenge (post by Jeremy Schneider) https://ardentperf.com/2024/03/03/postgres-indexes-partitioning-and-lwlocklockmanager-scalability
Increase 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-18
logerrors https://github.com/munakoiso/logerrors

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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 produced by:

Michael Christofides, founder of pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

Gadget's use of Postgres Sep 19, 2025

Show notes

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-brundage
Gadget https://gadget.dev
Zero downtime Postgres upgrades using logical replication (blog post) https://gadget.dev/blog/zero-downtime-postgres-upgrades-using-logical-replication
HOT updates https://www.postgresql.org/docs/current/storage-hot.html
PgDog https://pgdog.dev
Multigres https://multigres.com
Neki https://www.neki.dev
Running 10 Million PostgreSQL Indexes In Production (Heap blog post) https://www.heap.io/blog/running-10-million-postgresql-indexes-in-production
pgwatch2 (Postgres.ai Edition) https://gitlab.com/postgres-ai/pgwatch2
Advanced query insights on AlloyDB https://cloud.google.com/alloydb/docs/advanced-query-insights-overview
OrioleDB https://www.orioledb.com
Not 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 pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

turbopuffer Sep 12, 2025

Show notes

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-eskildsen
turbopuffer https://turbopuffer.com
Use ULID Idempotency Keys (tip 6 in this blog post from Shopify) https://shopify.engineering/building-resilient-payment-systems
PostgreSQL 18 Release Candidate 1 https://www.postgresql.org/about/news/postgresql-18-rc-1-released-3130
Understanding DiskANN (blog post by Junaid Ahmed) https://www.tigerdata.com/blog/understanding-diskann
SPFresh: Incremental In-Place Update for Billion-Scale Vector Search (paper) https://arxiv.org/abs/2410.14452
Amazon S3 adds new functionality for conditional writes https://aws.amazon.com/about-aws/whats-new/2024/11/amazon-s3-functionality-conditional-writes
Amazon 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 pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

When not to use Postgres Sep 05, 2025

Show notes

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-postgres
Just Use Postgres for Everything (blog post by Stephan Schmidt) https://www.amazingcto.com/postgres-for-everything
Real-time analytics episode https://postgres.fm/episodes/real-time-analytics
Crunchy Data Joins Snowflake https://www.crunchydata.com/blog/crunchy-data-joins-snowflake
Two sizes fit most: PostgreSQL and Clickhouse (blog post by Sid Sijbrandij) https://about.gitlab.com/blog/two-sizes-fit-most-postgresql-and-clickhouse
pg_duckdb episode https://postgres.fm/episodes/pg_duckdb
Cloudberry https://github.com/apache/cloudberry
Time-series considerations episode https://postgres.fm/episodes/time-series-considerations
Queues in Postgres episode https://postgres.fm/episodes/queues-in-postgres
Large Objects https://www.postgresql.org/docs/current/largeobjects.html
PGlite https://pglite.dev
ParadeDB https://www.paradedb.com
ZomboDB https://github.com/zombodb/zombodb
turbopuffer https://turbopuffer.com
HNSW vs. DiskANN (blog post by Haziqa Sajid) https://www.tigerdata.com/learn/hnsw-vs-diskann
SPANN: Highly-efficient Billion-scale Approximate Nearest Neighbor Search (paper) https://www.microsoft.com/en-us/research/wp-content/uploads/2021/11/SPANN_finalversion1.pdf
Amazon S3 Vectors https://aws.amazon.com/s3/features/vectors
Iterative Index Scans added to pgvector in 0.8.0 https://github.com/pgvector/pgvector/issues/678
S3 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 pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

Disks Aug 29, 2025

Show notes

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/1959468091035009245
Postgres LISTEN/NOTIFY does not scale (blog post by Recall ai) https://www.recall.ai/blog/postgres-listen-notify-does-not-scale
track_io_timing https://www.postgresql.org/docs/current/runtime-config-statistics.html#GUC-TRACK-IO-TIMING
pg_test_timing https://www.postgresql.org/docs/current/pgtesttiming.html
PlanetScale for Postgres https://planetscale.com/blog/planetscale-for-postgres
Out of disk episode https://postgres.fm/episodes/out-of-disk
100TB episode https://postgres.fm/episodes/to-100tb-and-beyond
Latency Numbers Every Programmer Should Know https://gist.github.com/jboner/2841832
Fio 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 pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

Multi-column indexes Aug 22, 2025

Show notes

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.html
Our episode on Index-only scans https://postgres.fm/episodes/index-only-scans
Combining Multiple Indexes (docs) https://www.postgresql.org/docs/current/indexes-bitmap-scans.html
Enable 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.html
Our episode on HOT updates https://postgres.fm/episodes/hot-updates
Our 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 pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

Self-driving Postgres Aug 15, 2025

Show notes

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-postgres
SAE J3016 levels of driving automation https://www.sae.org/news/2019/01/sae-updates-j3016-automated-driving-graphic
Oracle 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.pdf
PGTune 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

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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 produced by:

Michael Christofides, founder of pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

caSe-inSENsiTive Aug 08, 2025

Show notes

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.html
Our episode on over-indexing https://postgres.fm/episodes/over-indexing
Nondeterministic collations https://www.postgresql.org/docs/current/collation.html#COLLATION-NONDETERMINISTIC
How 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-collation
The collation versioning problem with ICU 73 (blog post by Daniel Vérité) https://postgresql.verite.pro/blog/2023/10/20/icu-73-versioning.html
amcheck https://www.postgresql.org/docs/current/amcheck.html

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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 produced by: