Michael Christofides
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michristofides.com
Michael Christofides
@michristofides.com
Half of the team behind @pgmustard.com and (a different) half of the team behind Postgres FM
Reposted by Michael Christofides
We've revamped our "Operation on Disk" tips ✨

* Made them clearer
* Made them more succinct (in most cases)
* Improved the scoring
* Mention hash_mem_multiplier (when relevant)
* Show "Operation in Memory" in more cases, with the memory used
* Updated the linked blog post
November 24, 2025 at 5:37 PM
I’m a heavy user of Things and a big fan of it! Recurring tasks have nice flexibility, you can choose either “every X”, or “Y after the last one was completed”.

Their reminders work well for me, but are only time based (some apps have location based reminders too).

Also no shared lists in Things
November 21, 2025 at 11:49 AM
Reposted by Michael Christofides
Big performance problems 🤝 tiny CS tricks

Our latest blog breaks down how bloom filters helped us take an API from 5s to 0.3s - even with millions of alerts in play.

If you’re fighting slow queries or Postgres under pressure, this one’s worth a look: go.incident.io/r9jgcI9
November 17, 2025 at 5:24 PM
Reposted by Michael Christofides
Today is the day -- end-of-life for Postgres 13

www.postgresql.org/support/vers...
November 14, 2025 at 1:49 AM
Reposted by Michael Christofides
Explain is a powerful tool in Postgres.

If you care about performance, get comfortable running `explain` and `explain analyze` commands regularly, and learn how to interpret its output.

This blog is a great intro.

www.depesz.com/2013/04/16/e...
November 4, 2025 at 2:59 PM
Reposted by Michael Christofides
I'm not sure @ankane.bsky.social is human - maybe some kind of open source being from the future 😂
I said to a colleague - "we'll see, but it's ankane, so it's entirely possible it'll get done soon". Less than an hour later, it was updated 🤯
November 12, 2025 at 1:18 AM
Reposted by Michael Christofides
New blog post: "What do the new Index Searches lines in EXPLAIN mean?"

In Postgres 18 you'll start seeing things like "Index Searches: 1" on each of your index scans. We looked into what they mean, and how that information can be helpful.

www.pgmustard.com/blog/what-do...
What do the new Index Searches lines in EXPLAIN mean? - pgMustard
In Postgres 18 you’ll now see “Index Searches” lines in EXPLAIN ANALYZE output. If like me you were wondering what those mean exactly, you’re in the right place.
www.pgmustard.com
November 10, 2025 at 1:23 PM
Reposted by Michael Christofides
2 million indexes! You’ve gotta listen to this in context of this Gadget episode with Harry — but that’s a wild figure! 😳

postgres.fm/episodes/gad...
Postgres FM | Gadget's use of Postgres
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 challen...
postgres.fm
September 28, 2025 at 7:18 PM
Hello! I really like pg_stat_statements, then you can look into your queries by all sorts of metrics (eg for read heavy workloads, ordering by total_exec_time is a good starting point). Then I like to run EXPLAIN (ANALYZE, BUFFERS, etc) on the worst offender(s) to look for optimizations
September 24, 2025 at 12:47 PM
Reposted by Michael Christofides
Sometimes the trick to optimizing database queries is simple: Don't do stupid stuff.
August 28, 2025 at 2:28 PM
I'm a bit out of date on the SQL Server side of things, but with Postgres have you already tried turning on track_io_timing and using more of the EXPLAIN parameters?

For example:

set track_io_timing = on;
explain (analyze, buffers, verbose, settings, wal) ...
September 3, 2025 at 11:13 AM
Reposted by Michael Christofides
The upcoming Postgres 18 is set to include some nice improvements to EXPLAIN:

* BUFFERS on by default with ANALYZE 🎉
* Fractional "actual rows" (huge in some cases)
* Quite a few new fields (including the very cool Index Searches)

We've now added support for all of them. 💛
August 20, 2025 at 2:40 PM
Reposted by Michael Christofides
Amazing post on making Postgres slower (yes, slower!) on purpose. byteofdev.com/posts/making... #postgres #postgresql Favorite bit: "random_page_cost = 1e300" LOL! Well done
Making Postgres 42,000x slower because I am unemployed
As an respectable unemployed person must do, I tried to make Postgres as slow as possible
byteofdev.com
July 28, 2025 at 2:51 PM
Reposted by Michael Christofides
Really non-trivial case with MultiXacts and brilliant RCA and level of transparency from the Metronome team – great example of what to do with new types of #PostgreSQL incidents!

enjoyed discussion a lot! www.youtube.com/watch?v=9KoP...
MultiXact member space exhaustion | Postgres.FM 151 | #PostgreSQL #Postgres podcast
YouTube video by PostgresTV
www.youtube.com
July 18, 2025 at 6:43 PM
Reposted by Michael Christofides
PostgresFM with Sugu, co-creator of Vitess, originally created to shard MySQL in YouTube, and then used by GitHub, Pinterest, Slack, Shopify, etc. Discussed his work at Supabase on Multigres, sharding for PostgreSQL. Enjoyed a lot!! Take it to a long hike or drive: youtu.be/KOepJivmWTg?...
Multigres | Postgres.FM 150 | #PostgreSQL #Postgres podcast
YouTube video by PostgresTV
youtu.be
July 11, 2025 at 4:13 PM
Reposted by Michael Christofides
3 years of PostgresFM 🥳

And now, @michristofides.com being back from 2-week break, and we've recorded our 150th episode

A very interesting one, don't miss -- this Friday
July 9, 2025 at 1:32 AM
Reposted by Michael Christofides
Postgres Meetup for All tomorrow www.meetup.com/postgres-mee...
July 8, 2025 at 3:58 PM
Reposted by Michael Christofides
Amazing talk by Alexander Kukushkin about caveats and myths and truths of sync replication in Postgres.

Everyone who works or plans to work with sync replication must watch it!

www.youtube.com/watch?v=PFn9...
Myths and Truths about Synchronous Replication in PostgreSQL | POSETTE: An Event for Postgres 2025
YouTube video by Microsoft Developer
www.youtube.com
July 6, 2025 at 11:35 PM
Reposted by Michael Christofides
There are a couple of online #PostgreSQL events today that look like they'll be great:

16:00 UTC — 10 Costly Database Performance Mistakes (and How to Fix Them) with Andy Atkinson www.meetup.com/postgres-mee...

19:00 UTC — 12 years of Postgres Weekly with Peter Cooper aka.ms/TalkingPostg...
June 18, 2025 at 2:16 PM
Reposted by Michael Christofides
Hello, Bluesky!
June 18, 2025 at 2:15 PM
Congrats Jimmy!
June 12, 2025 at 8:29 AM
Reposted by Michael Christofides
I have the great pleasure to announce the release of PostgreSQL Mistakes and How to Avoid Them in all formats! 🎉 To celebrate, @manningbooks.bsky.social is offering a Deal of the Day: 45% off my book and other selected titles! 👉 mng.bz/WrEx

#PostgreSQL #Postgres #TechBooks #Database #OpenSource
Deal of the Day
Manning is an independent publisher of computer books, videos, and courses.
mng.bz
June 12, 2025 at 8:23 AM
Is min short for minimum, or minutes?!!
May 14, 2025 at 1:17 PM
Well I really like your framing, and other AI techniques like ML seem to mostly have almost the opposite characteristics (can get better than even the most specialised humans, but only at very narrow/highly constrained tasks!)
May 13, 2025 at 2:59 PM
Very nicely put! It only strengthens your point, but I don’t think chess is even a counter example (other AI techniques sure, just not LLMs)
May 13, 2025 at 9:38 AM