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

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

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