Horton

Re: [PING] fallocate() causes btrfs to never compress postgresql files

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Magnus Hagander <magnus@hagander.net>
Cc: Dimitrios Apostolou <jimis@gmx.net>, Tomas Vondra <tomas@vondra.me>, pgsql-hackers@lists.postgresql.org, Andres Freund <andres@anarazel.de>, Melanie Plageman <melanieplageman@gmail.com>, Heikki Linnakangas <hlinnaka@iki.fi>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, David Rowley <dgrowleyml@gmail.com>
Date: 2025-08-05T13:07:57Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Add file_extend_method=posix_fallocate,write_zeros.

  2. Add smgrzeroextend(), FileZero(), FileFallocate()

On Tue, Jul 29, 2025 at 6:52 PM Magnus Hagander <magnus@hagander.net> wrote:
> Not just to throw a wrench in there, but... Should this perhaps be a tablespace option? ISTM having different filesystems for them is a good reason to use tablespaces in the first place, and then being able to pick different options...

We discussed that a bit earlier in the thread.  Some problems about
layering violations and general weirdness, I recall trying it even.
On the flip side, is it right to declare very local
filesystem-specific choices in a system catalogue that is replicated
and affects replicas?
What about a fancier GUC that can reference tablespaces?