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From: Dapeng Wang <wangdp20191008@gmail.com>
Date: Sat, 11 Apr 2026 20:19:55 +0800
Message-ID: 
 <CAKx0Yhzmn=gdfsv7iZDZ1cjXqRLq0amUmESL83qjyxnFDqYVJQ@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=8811=E6=97=
=A5=E5=91=A8=E5=85=AD 13:02=E5=86=99=E9=81=93=EF=BC=9A

> Hi,
>
> On Fri, Apr 10, 2026 at 4:57=E2=80=AFAM Dapeng Wang <wangdp20191008@gmail=
.com>
> wrote:
>
>> 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?
>>
>
> Updated the patch covering those two as well.
>
>
> Regards,
> Lakshmi
>


Hi Lakshmi,

The updated patch now covers all four catalog scan loops.
Applies cleanly, compiles without warnings, and all 247
regression tests pass.

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=
=8811=E6=97=A5=E5=91=A8=E5=85=AD 13:02=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"><div dir=3D"ltr">Hi,</div><br><div cla=
ss=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Fri, Apr 10, 20=
26 at 4:57=E2=80=AFAM Dapeng Wang &lt;<a href=3D"mailto:wangdp20191008@gmai=
l.com" target=3D"_blank">wangdp20191008@gmail.com</a>&gt; wrote:<br></div><=
blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-l=
eft:1px solid rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div dir=
=3D"ltr">Lakshmi N &lt;<a href=3D"mailto:lakshmin.jhs@gmail.com" target=3D"=
_blank">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 clas=
s=3D"gmail_quote"><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px=
 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div di=
r=3D"ltr">Hi hackers,<div><br></div><div>I noticed CFI is missing=C2=A0whil=
e scanning pg_class for RELKIND_RELATION and RELKIND_TOASTVALUE. On a datab=
ase with several thousands of tables, these scans can take a noticeable amo=
unt of time. Attached a patch to address this.</div><div><br></div><div>Reg=
ards,</div><div>Lakshmi</div></div></blockquote>Hi Lakshmi,<br><br>The patc=
h applies cleanly to HEAD and compiles without warnings.<br>make check pass=
es (one unrelated ICU collation diff).<br><br>The two CHECK_FOR_INTERRUPTS(=
) additions in do_autovacuum() look<br>correct and are well-placed at the t=
op of each loop iteration,<br>before any resources are acquired.<br><br>I n=
oticed there are other similar catalog scan loops in<br>autovacuum.c that a=
lso lack CHECK_FOR_INTERRUPTS():<br><br>- The pg_database scan loop around =
line 1854<br>- The pg_class scan loop around line 3664<br><br>Should those =
be covered as well?<br></div></div></blockquote><div><br></div><div>Updated=
 the patch covering those two as well.</div><div><br></div><div><br></div><=
div>Regards,</div><div>Lakshmi</div></div></div></blockquote><div><br></div=
><div><br></div>Hi Lakshmi,<br><br>The updated patch now covers all four ca=
talog scan loops.<br>Applies cleanly, compiles without warnings, and all 24=
7<br>regression tests pass.<br><br>Regards,<br><div>Dapeng Wang=C2=A0</div>=
</div></div>

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