Postgres FM

Latest Episodes:

pg_ash Feb 20, 2026

Show notes

Nik and Michael discuss pg_ash — a new tool (not extension!) from Nik that samples and stores wait events from pg_stat_activity.
Here are some links to things they mentioned:

pg_ash https://github.com/NikolayS/pg_ash
pg_wait_sampling https://github.com/postgrespro/pg_wait_sampling
Amazon RDS performance insights https://aws.amazon.com/rds/performance-insights
Our episode on wait events https://postgres.fm/episodes/wait-events
pg-flight-recorder https://github.com/dventimisupabase/pg-flight-recorder
pg_profile https://github.com/zubkov-andrei/pg_profile
pg_cron https://github.com/citusdata/pg_cron

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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

Comments and metadata Feb 13, 2026

Show notes

Nik and Michael discuss query level comments, object level comments, and another way of adding object level metadata.
Here are some links to things they mentioned:

Object comments https://www.postgresql.org/docs/current/sql-comment.html
Query comment syntax (from an old version of the docs) https://www.postgresql.org/docs/7.0/syntax519.htm
SQL Comments, Please! (Post by Markus Winand) https://modern-sql.com/caniuse/comments
“While C-style block comments are passed to the server for processing and removal, SQL-standard comments are removed by psql.” https://www.postgresql.org/docs/current/app-psql.html
marginalia https://github.com/basecamp/marginalia
track_activity_query_size https://www.postgresql.org/docs/current/runtime-config-statistics.html#GUC-TRACK-ACTIVITY-QUERY-SIZE
Custom Properties for Database Objects Using SECURITY LABELS (post by Andrei Lepikhov) https://www.pgedge.com/blog/custom-properties-for-postgresql-database-objects-without-core-patches

~~~

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

PgDog update Jan 23, 2026

Show notes

Nik and Michael are joined by Lev Kokotov for an update on all things PgDog.
Here are some links to things they mentioned:

Lev Kokotov https://postgres.fm/people/lev-kokotov
PgDog https://github.com/pgdogdev/pgdog
Our first PgDog episode (March 2025) https://postgres.fm/episodes/pgdog
Sharding pgvector (blog post by Lev) https://pgdog.dev/blog/sharding-pgvector
Prepared statements and partitioned table lock explosion (series by Nik) https://postgres.ai/blog/20251028-postgres-marathon-2-009

~~~

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

RegreSQL Jan 16, 2026

Show notes

Nik and Michael are joined by Radim Marek from boringSQL to talk about RegreSQL, a regression testing tool for SQL queries they forked and improved recently.
Here are some links to things they mentioned:

Radim Marek https://postgres.fm/people/radim-marek
boringSQL https://boringsql.com
RegreSQL: Regression Testing for PostgreSQL Queries (blog post by Radim) https://boringsql.com/posts/regresql-testing-queries
Discussion on Hacker News https://news.ycombinator.com/item?id=45924619
Radim’s fork of RegreSQL on GitHub https://github.com/boringSQL/regresql
Original RegreSQL on GitHub (by Dimitri Fontaine) https://github.com/dimitri/regresql
The Art of PostgreSQL (book) https://theartofpostgresql.com
How to make the non-production Postgres planner behave like in production (how-to post by Nik) https://postgres.ai/docs/postgres-howtos/performance-optimization/query-tuning/how-to-imitate-production-planner
Just because you’re getting an index scan, doesn't mean you can’t do better! (Blog post by Michael) https://www.pgmustard.com/blog/index-scan-doesnt-mean-its-fast
boringSQL Labs https://labs.boringsql.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 pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

Postgres year in review 2025 Jan 02, 2026

Show notes

Nik and Michael discuss the events and trends they thought were most important in the Postgres ecosystem in 2025.
Here are some links to things they mentioned:

Postgres 18 release notes https://www.postgresql.org/docs/18/release-18.html
Our episode on Postgres 18 https://postgres.fm/episodes/postgres-18
LWLock:LockManager benchmarks for Postgres 18 (blog post by Nik) https://postgres.ai/blog/20251009-postgres-marathon-2-005
PostgreSQL bug tied to zero-day attack on US Treasury https://www.theregister.com/2025/02/14/postgresql_bug_treasury
PgDog episode https://postgres.fm/episodes/pgdog
Multigres episode https://postgres.fm/episodes/multigres
Neki announcement https://planetscale.com/blog/announcing-neki
Our 100TB episode from 2024 https://postgres.fm/episodes/to-100tb-and-beyond
PlanetScale for Postgres https://planetscale.com/blog/planetscale-for-postgres
Oracle's MySQL job cuts https://www.theregister.com/2025/09/11/oracle_slammed_for_mysql_job
Amazon Aurora DSQL is now generally available https://aws.amazon.com/about-aws/whats-new/2025/05/amazon-aurora-dsql-generally-available
Announcing Azure HorizonDB https://techcommunity.microsoft.com/blog/adforpostgresql/announcing-azure-horizondb/4469710
Lessons from Replit and Tiger Data on Storage for Agentic Experimentation https://www.tigerdata.com/blog/lessons-replit-tiger-data-storage-agentic-experimentation
Instant database clones with PostgreSQL 18 https://boringsql.com/posts/instant-database-clones
turbopuffer episode https://postgres.fm/episodes/turbopuffer
Crunchy joins Snowflake https://www.crunchydata.com/blog/crunchy-data-joins-snowflake
Neon joins Databricks https://neon.com/blog/neon-and-databricks

~~~

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

Archiving Dec 19, 2025

Show notes

Nik and Michael discuss a listener question about archiving a database.
Here are some links to things they mentioned:

Listener request to talk about archiving https://www.youtube.com/watch?v=KFRK8PiIvTg&lc=UgyiFrO37gEgUaVhRgN4AaABAg
Our episode on “Is pg_dump a backup tool?” https://postgres.fm/episodes/is-pg_dump-a-backup-tool

~~~

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

max_connections vs migrations Dec 05, 2025

Show notes

Nik and Michael discuss max_connections, especially in the context of increasing it to solve problems like migrations intermittently failing(!)
Here are some links to things they mentioned:

max_connections https://www.postgresql.org/docs/current/runtime-config-connection.html#GUC-MAX-CONNECTIONS
Tweet about deployments vs connections issue https://x.com/brankopetric00/status/1991394329886077090
Nik tweet in response https://x.com/samokhvalov/status/1991465573684027443
Analyzing the Limits of Connection Scalability in Postgres (blog post by Andres Freund) https://www.citusdata.com/blog/2020/10/08/analyzing-connection-scalability/
Exponential Backoff And Jitter (blog post by Marc Brooker) https://aws.amazon.com/blogs/architecture/exponential-backoff-and-jitter/

~~~

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

What's new in EXPLAIN Nov 21, 2025

Show notes

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.html
Using EXPLAIN (official docs) https://www.postgresql.org/docs/current/using-explain.html
EXPLAIN glossary (pgMustard site) https://www.pgmustard.com/docs/explain
Postgres 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=c2a4078eb
Our (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=0fbceae841cb5a31b13d3f284ac8fdd19822eceb
Our episode on Skip scan with Peter Geoghegan https://postgres.fm/episodes/skip-scan
What do the new Index Searches lines in EXPLAIN mean? https://www.pgmustard.com/blog/what-do-index-searches-in-explain-mean
pg_stat_plans presentation by Lukas Fittl https://www.youtube.com/watch?v=26coQV3f-wk
Improve EXPLAIN's display of window functions (commit) https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=8b1b34254
Show Parallel Bitmap Heap Scan worker stats in EXPLAIN ANALYZE (commit) https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=5a1e6df3b
Add 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 pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

Tens of TB per hour Nov 14, 2025

Show notes

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-pgbackrest
Copying a database episode https://postgres.fm/episodes/copying-a-database
Add snapshot backup support for PostgreSQL in wal-g (draft PR by Andrey Borodin) https://github.com/wal-g/wal-g/pull/2101
Multi-threaded pg_basebackup discussion 1: https://www.postgresql.org/message-id/flat/CAEHH7R4%3D_GN%2BLSsj0YZOXZ13yc%3DGk9umJOLNopjS%3DimK0c1mWA%40mail.gmail.com
Multi-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/pgbackrest
Add 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 pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

Gapless sequences Oct 31, 2025

Show notes

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.html
Sequence Manipulation Functions https://www.postgresql.org/docs/current/functions-sequence.html
One, Two, Skip a Few (post by Pete Hamilton from Incident io) https://incident.io/blog/one-two-skip-a-few
Postgres sequences can commit out-of-order (blog post by Anthony Accomazzo / Sequin) https://blog.sequinstream.com/postgres-sequences-can-commit-out-of-order
Logical Replication of sequences (hackers thread) https://www.postgresql.org/message-id/flat/CAA4eK1LC%2BKJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ%40mail.gmail.com
Synchronization 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-create
German 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 pgMustard
Nikolay Samokhvalov, founder of Postgres.ai

With credit to:

Jessie Draws for the elephant artwork

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