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

Thomas Munro <thomas.munro@gmail.com>

From: Thomas Munro <thomas.munro@gmail.com>

To: Dimitrios Apostolou <jimis@gmx.net>

Cc: Magnus Hagander <magnus@hagander.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: 2025-10-30T03:55:29Z

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 →

Add file_extend_method=posix_fallocate,write_zeros.
- e37b59802846 16.12 landed
- 4dac22aa10d2 17.8 landed
- f94e9141a0bb 19 (unreleased) landed
- 33e3de6d77e8 18.2 landed
Add smgrzeroextend(), FileZero(), FileFallocate()
- 4d330a61bb19 16.0 cited

On Wed, Oct 29, 2025 at 4:31 AM Dimitrios Apostolou <jimis@gmx.net> wrote:
> Sorry to ping again, but was there a conclusion reached regarding adding the new file_extend_method setting?

No objections appeared, so the conclusion I am drawing is that we
should do this, and back-patch it into 17 for the upcoming release.
It is working as expected on my ZFS system in light testing.  Rebasing
and figuring out where to add the missing documentation for last
chance review...