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
New blog post: Read efficiency issues in Postgres queries
If you've got a query that's slowly degrading in performance, you might have a read efficiency issue. The root cause could be table bloat, index bloat, or data locality degradation.
www.pgmustard.com/blog/read-ef...
If you've got a query that's slowly degrading in performance, you might have a read efficiency issue. The root cause could be table bloat, index bloat, or data locality degradation.
www.pgmustard.com/blog/read-ef...
Read efficiency issues in Postgres queries - pgMustard
A lot of the time in database land, our queries are I/O constrained. As such, performance work often involves reducing the number of page reads. Indexes are a prime example, but they don’t solve every...
www.pgmustard.com
February 13, 2026 at 1:22 PM
New blog post: Read efficiency issues in Postgres queries
If you've got a query that's slowly degrading in performance, you might have a read efficiency issue. The root cause could be table bloat, index bloat, or data locality degradation.
www.pgmustard.com/blog/read-ef...
If you've got a query that's slowly degrading in performance, you might have a read efficiency issue. The root cause could be table bloat, index bloat, or data locality degradation.
www.pgmustard.com/blog/read-ef...
Reposted by Michael Christofides
Over on threads someone just use ai;dr and we all need to adopt that right quick
February 11, 2026 at 7:56 PM
Over on threads someone just use ai;dr and we all need to adopt that right quick
Reposted by Michael Christofides
Our Read Efficiency tips are now more efficient to read!
📝 Better wording, mostly for clarity
🔬 More specific to the scan type, and therefore shorter in most cases
🌟 Improved scoring, especially for Bitmap Heap Scans
More details: www.pgmustard.com/changelog
📝 Better wording, mostly for clarity
🔬 More specific to the scan type, and therefore shorter in most cases
🌟 Improved scoring, especially for Bitmap Heap Scans
More details: www.pgmustard.com/changelog
January 20, 2026 at 4:14 PM
Our Read Efficiency tips are now more efficient to read!
📝 Better wording, mostly for clarity
🔬 More specific to the scan type, and therefore shorter in most cases
🌟 Improved scoring, especially for Bitmap Heap Scans
More details: www.pgmustard.com/changelog
📝 Better wording, mostly for clarity
🔬 More specific to the scan type, and therefore shorter in most cases
🌟 Improved scoring, especially for Bitmap Heap Scans
More details: www.pgmustard.com/changelog
If you have any Postgres performance issues, I'd love to hear about them and try to help: pgmustard.com/office-hours
Office hours - pgMustard
For January, I’m offering a private free call (up to 1 hour) to discus anything Postgres performance related.
pgmustard.com
January 6, 2026 at 2:49 PM
If you have any Postgres performance issues, I'd love to hear about them and try to help: pgmustard.com/office-hours
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
* 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
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
* 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
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
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
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
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
Reposted by Michael Christofides
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...
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
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...
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...
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 🤯
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
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 🤯
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 🤯
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...
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
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...
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...
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/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
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/episodes/gad...
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
Sometimes the trick to optimizing database queries is simple: Don't do stupid stuff.
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. 💛
* 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
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. 💛
* 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. 💛
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
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
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...
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
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...
enjoyed discussion a lot! www.youtube.com/watch?v=9KoP...
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
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?...
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
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
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
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
Reposted by Michael Christofides
Postgres Meetup for All tomorrow www.meetup.com/postgres-mee...
July 8, 2025 at 3:58 PM
Postgres Meetup for All tomorrow www.meetup.com/postgres-mee...
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...
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
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...
Everyone who works or plans to work with sync replication must watch it!
www.youtube.com/watch?v=PFn9...
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...
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
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...
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...
Reposted by Michael Christofides
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
#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
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
#PostgreSQL #Postgres #TechBooks #Database #OpenSource
Next week (14th) I'll be joining the excellent Postgres Meetup for All to demo and discuss troubleshooting slow queries using EXPLAIN and external tools: www.meetup.com/postgres-mee...
If you or your team could do with an intro or refresher, it would be great to see you there!
If you or your team could do with an intro or refresher, it would be great to see you there!
Postgres Meetup for All | Meetup
Calling all Postgres enthusiasts! Do you work with Postgres? Do you want to be more involved in the community? Share your learnings? Join our vibrant online community dedicated to PostgreSQL, the worl...
www.meetup.com
May 7, 2025 at 4:21 PM
Next week (14th) I'll be joining the excellent Postgres Meetup for All to demo and discuss troubleshooting slow queries using EXPLAIN and external tools: www.meetup.com/postgres-mee...
If you or your team could do with an intro or refresher, it would be great to see you there!
If you or your team could do with an intro or refresher, it would be great to see you there!
Reposted by Michael Christofides
I'm proud to announce that I'm teaching a 1-day Postgres performance tuning class at the PASS Summit this year! Registration is open now, and if you register before May 13, you save big with early bird rates. passdatacommunitysummit.com/sessions/1103
All sessions - PASS Data Community Summit
passdatacommunitysummit.com
April 29, 2025 at 8:49 PM
I'm proud to announce that I'm teaching a 1-day Postgres performance tuning class at the PASS Summit this year! Registration is open now, and if you register before May 13, you save big with early bird rates. passdatacommunitysummit.com/sessions/1103