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Subject: Re: [Proposal] Adding callback support for custom statistics kinds
From: Chao Li <li.evan.chao@gmail.com>
In-Reply-To: <aTepXZ97PsXpuywI@paquier.xyz>
Date: Tue, 9 Dec 2025 13:23:56 +0800
Cc: Sami Imseih <samimseih@gmail.com>,
 PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
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To: Michael Paquier <michael@paquier.xyz>
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> On Dec 9, 2025, at 12:45, Michael Paquier <michael@paquier.xyz> wrote:
>=20
> It seems to me that you are missing nothing here, and that Chao has
> missed the fact that the end of pgstat_read_statsfile() does a "goto
> done", meaning that we would take a round of

No, I didn=E2=80=99t miss that part. But in the =E2=80=9Cdone=E2=80=9D =
clause:

```
done:
/* First, cleanup the main stats file, PGSTAT_STAT_PERMANENT_FILENAME */
FreeFile(fpin);

elog(DEBUG2, "removing permanent stats file \"%s\"", statfile);
unlink(statfile);

/* Let each stats kind run its cleanup callback, if it provides one */
for (PgStat_Kind kind =3D PGSTAT_KIND_MIN; kind <=3D PGSTAT_KIND_MAX; =
kind++)
{
const PgStat_KindInfo *kind_info =3D pgstat_get_kind_info(kind);

if (kind_info && kind_info->end_extra_stats)
kind_info->end_extra_stats(STATS_READ);
}
```

end_extra_stats(STATS_READ) has no failure indication.

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/