Re: Vacuum ERRORs out considering freezing dead tuples from before OldestXmin

Melanie Plageman <melanieplageman@gmail.com>

From: Melanie Plageman <melanieplageman@gmail.com>

To: John Naylor <johncnaylorls@gmail.com>

Cc: Peter Geoghegan <pg@bowt.ie>, Pg Hackers <pgsql-hackers@postgresql.org>, Andres Freund <andres@anarazel.de>, Noah Misch <noah@leadboat.com>

Date: 2025-06-16T14:58:21Z

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 →

Test that vacuum removes tuples older than OldestXmin
- 2c0bc4765741 17.6 landed
- 303ba0573ce6 18.0 landed
- 80c34692e8e6 17.0 landed
- aa607980aee0 18.0 landed
Lower minimum maintenance_work_mem to 64kB
- 2eda3df9ad53 17.0 landed
- bbf668d66fbf 18.0 landed
Add accidentally omitted test to meson build file
- 9d198f4d3e3b 16.4 landed
Use DELETE instead of UPDATE to speed up vacuum test
- 924a08b76f5d 14.13 landed
- 9744fe24118b 15.8 landed
- 571e0ee40ebd 16.4 landed
Revert "Test that vacuum removes tuples older than OldestXmin"
- efcbb76efe40 18.0 landed
- 1a3e90948b50 17.0 landed
Ensure vacuum removes all visibly dead tuples older than OldestXmin
- fd4f12df5e46 17.0 landed
- 83c39a1f7f3f 18.0 landed

Attachments

v1-Test-that-vacuum-removes-tuples-older-than-OldestXmi.patch (text/x-patch) patch v1

On Fri, Jun 13, 2025 at 10:12 AM John Naylor <johncnaylorls@gmail.com> wrote:
>
> (Swapping this part back in my brain as well...) I actually don't
> think we need that where clause anymore since mwm can be super low
> now, and it's a bit mysterious what it was trying to accomplish. Maybe
> we can just use the lowest fill factor to reduce WAL -- having a few
> dozen pages should push it over the memory limit, regardless of how
> many dead tuples are on each pages.

Test in attached patch seems to do the job on 32 bit and 64 bit when tested.

- Melanie