Date: Thu, 8 Jan 2026 18:36:13 +0100
From: Michael Banck <mbanck@gmx.net>
To: Soumya S Murali <soumyamurali.work@gmail.com>
Cc: Fujii Masao <masao.fujii@gmail.com>,
	VASUKI M <vasukianand0119@gmail.com>,
	Andres Freund <andres@anarazel.de>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
	=?utf-8?Q?=C3=81lvaro?= Herrera <alvherre@kurilemu.de>,
	melanieplageman@gmail.com, juanjo.santamaria@gmail.com
Subject: Re: [PATCH] Expose checkpoint reason to completion log messages.
Message-ID: <20260108173613.GE30363@p46.dedyn.io;lightning.p46.dedyn.io>
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Archived-At: <https://www.postgresql.org/message-id/20260108173613.GE30363%40p46.dedyn.io%3Blightning.p46.dedyn.io>
Precedence: bulk

Hi,

On Thu, Jan 08, 2026 at 11:58:43AM +0530, Soumya S Murali wrote:
> On Wed, Jan 7, 2026 at 1:37=E2=80=AFPM Michael Banck <mbanck@gmx.net> wr=
ote:
> > On Wed, Jan 07, 2026 at 12:35:08PM +0530, Soumya S Murali wrote:
> I have reworked the patch to factor out the checkpoint reason logic to
> use the same wording for both checkpoint start and completion log
> (including wal, time, fast, force, and wait). The format has been
> aligned with existing conventions and has been verified by running
> make check and recovery TAP tests including t/019_replslot_limit.pl
> successfully.
> Kindly review my patch and let me know the feedback.

Thanks for the new patch.

> index 22d0a2e8c3..9f7439f9a2 100644
> --- a/src/backend/access/transam/xlog.c
> +++ b/src/backend/access/transam/xlog.c
[...]
> +static const char *
> +CheckpointReasonString(int flags)
> +{
> +	static char buf[128];
> +
> +	buf[0] =3D '\0';
> +
> +	if (flags & CHECKPOINT_IS_SHUTDOWN)
> +		strcat(buf, " shutdown");
> +	if (flags & CHECKPOINT_END_OF_RECOVERY)
> +		strcat(buf, " end-of-recovery");
> +	if (flags & CHECKPOINT_FAST)
> +		strcat(buf, " fast");
> +	if (flags & CHECKPOINT_FORCE)
> +		strcat(buf, " force");
> +	if (flags & CHECKPOINT_WAIT)
> +		strcat(buf, " wait");
> +	if (flags & CHECKPOINT_CAUSE_XLOG)
> +		strcat(buf, " wal");
> +	if (flags & CHECKPOINT_CAUSE_TIME)
> +		strcat(buf, " time");
> +	if (flags & CHECKPOINT_FLUSH_UNLOGGED)
> +		strcat(buf, " flush-unlogged");
> +
> +	return buf;
> +}

The way this is coded now prepends the final string with a space
character. This is fine for the checkpoint starting message, but makes
the checkpoint finished message look slightly weird (not the "( wal)"):

|2026-01-08 18:30:33.691 CET [1666416] LOG:  checkpoint complete ( wal):
|wrote 20 buffers (0.1%), wrote 0 SLRU buffers; 0 WAL file(s) added, 4
|removed, 33 recycled; write=3D2.221 s, sync=3D0.019 s, total=3D2.701 s; s=
ync
|files=3D3, longest=3D0.018 s, average=3D0.007 s; distance=3D601885 kB,
|estimate=3D601885 kB; lsn=3D0/D2D59FC8, redo lsn=3D0/B492B500

Also I think the translators might now complain, but I am not sure how
to best approach this.


Michael