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From: Dapeng Wang <wangdp20191008@gmail.com>
Date: Fri, 10 Apr 2026 19:57:22 +0800
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 <CAKx0YhxRYuWCSC3mCTJ0VRn0iM8v0G=7vku=3Wg7pyi+rN-=Jw@mail.gmail.com>
Subject: Re: Add missing CHECK_FOR_INTERRUPTS in autovacuum catalog scan loops
To: Lakshmi N <lakshmin.jhs@gmail.com>
Cc: pgsql-hackers@lists.postgresql.org
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Lakshmi N <lakshmin.jhs@gmail.com> =E4=BA=8E2026=E5=B9=B44=E6=9C=8810=E6=97=
=A5=E5=91=A8=E4=BA=94 16:39=E5=86=99=E9=81=93=EF=BC=9A

> Hi hackers,
>
> I noticed CFI is missing while scanning pg_class for RELKIND_RELATION and
> RELKIND_TOASTVALUE. On a database with several thousands of tables, these
> scans can take a noticeable amount of time. Attached a patch to address
> this.
>
> Regards,
> Lakshmi
>
Hi Lakshmi,

The patch applies cleanly to HEAD and compiles without warnings.
make check passes (one unrelated ICU collation diff).

The two CHECK_FOR_INTERRUPTS() additions in do_autovacuum() look
correct and are well-placed at the top of each loop iteration,
before any resources are acquired.

I noticed there are other similar catalog scan loops in
autovacuum.c that also lack CHECK_FOR_INTERRUPTS():

- The pg_database scan loop around line 1854
- The pg_class scan loop around line 3664

Should those be covered as well?

Regards,
Dapeng Wang

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<div dir=3D"ltr"><div dir=3D"ltr">Lakshmi N &lt;<a href=3D"mailto:lakshmin.=
jhs@gmail.com">lakshmin.jhs@gmail.com</a>&gt; =E4=BA=8E2026=E5=B9=B44=E6=9C=
=8810=E6=97=A5=E5=91=A8=E4=BA=94 16:39=E5=86=99=E9=81=93=EF=BC=9A</div><div=
 class=3D"gmail_quote gmail_quote_container"><blockquote class=3D"gmail_quo=
te" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204=
);padding-left:1ex"><div dir=3D"ltr">Hi hackers,<div><br></div><div>I notic=
ed CFI is missing=C2=A0while scanning pg_class for RELKIND_RELATION and REL=
KIND_TOASTVALUE. On a database with several thousands of tables, these scan=
s can take a noticeable amount of time. Attached a patch to address this.</=
div><div><br></div><div>Regards,</div><div>Lakshmi</div></div></blockquote>=
Hi Lakshmi,<br><br>The patch applies cleanly to HEAD and compiles without w=
arnings.<br>make check passes (one unrelated ICU collation diff).<br><br>Th=
e two CHECK_FOR_INTERRUPTS() additions in do_autovacuum() look<br>correct a=
nd are well-placed at the top of each loop iteration,<br>before any resourc=
es are acquired.<br><br>I noticed there are other similar catalog scan loop=
s in<br>autovacuum.c that also lack CHECK_FOR_INTERRUPTS():<br><br>- The pg=
_database scan loop around line 1854<br>- The pg_class scan loop around lin=
e 3664<br><br>Should those be covered as well?<br><br>Regards,<br><div>Dape=
ng Wang=C2=A0</div></div></div>

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