Re: CHECKPOINT unlogged data

Christoph Berg <myon@debian.org>

From: Christoph Berg <myon@debian.org>

To: Fujii Masao <masao.fujii@oss.nttdata.com>

Cc: Andres Freund <andres@anarazel.de>, Nathan Bossart <nathandbossart@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2025-06-06T14:26:56Z

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 FLUSH_UNLOGGED option to CHECKPOINT command.
- 8d33fbacbac9 19 (unreleased) landed
Add MODE option to CHECKPOINT command.
- 2f698d7f4b7b 19 (unreleased) landed
Add option list to CHECKPOINT command.
- a4f126516e68 19 (unreleased) landed
Rename CHECKPOINT_FLUSH_ALL to CHECKPOINT_FLUSH_UNLOGGED.
- cd8324cc89a9 19 (unreleased) landed
Rename CHECKPOINT_IMMEDIATE to CHECKPOINT_FAST.
- bb938e2c3c7a 19 (unreleased) landed

Attachments

v3-0001-Add-mode-and-flush_all-options-to-checkpoint.patch (text/x-diff)

Re: Fujii Masao
> utility.c:946:4: warning: label followed by a declaration is a C23 extension [-Wc23-extensions]

Thanks, my compiler didn't throw that. { } block added in v3.

> 			RequestCheckpoint(CHECKPOINT_WAIT |
> +							  (immediate ? CHECKPOINT_IMMEDIATE : 0) |
> +							  (flush_all ? CHECKPOINT_FLUSH_ALL : 0) |
> 
> Some users might want to trigger a spread checkpoint but not wait for
> it to finish, since it could take a long time? If that's a valid use case,
> maybe we should add a WAIT option to let users choose whether to wait for
> the checkpoint to complete or not?

Do we want that? The checkpoint is only effective when it's finished,
and running `psql -c "checkpoint (wait false)"` might make people
shoot themselves into the foot.

Christoph