Thread

1. Add missing CHECK_FOR_INTERRUPTS in autovacuum catalog scan loops

   Lakshmi N <lakshmin.jhs@gmail.com> — 2026-04-10T08:38:53Z

   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
   

2. Re: Add missing CHECK_FOR_INTERRUPTS in autovacuum catalog scan loops

   Dapeng Wang <wangdp20191008@gmail.com> — 2026-04-10T11:57:22Z

   Lakshmi N <lakshmin.jhs@gmail.com> 于2026年4月10日周五 16:39写道：
   
   > 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
   

3. Re: Add missing CHECK_FOR_INTERRUPTS in autovacuum catalog scan loops

   Lakshmi N <lakshmin.jhs@gmail.com> — 2026-04-11T05:02:02Z

   Hi,
   
   On Fri, Apr 10, 2026 at 4:57 AM Dapeng Wang <wangdp20191008@gmail.com>
   wrote:
   
   > Lakshmi N <lakshmin.jhs@gmail.com> 于2026年4月10日周五 16:39写道：
   >
   >> 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
   
   >
   

4. Re: Add missing CHECK_FOR_INTERRUPTS in autovacuum catalog scan loops

   Dapeng Wang <wangdp20191008@gmail.com> — 2026-04-11T12:19:55Z

   Lakshmi N <lakshmin.jhs@gmail.com> 于2026年4月11日周六 13:02写道：
   
   > Hi,
   >
   > On Fri, Apr 10, 2026 at 4:57 AM Dapeng Wang <wangdp20191008@gmail.com>
   > wrote:
   >
   >> Lakshmi N <lakshmin.jhs@gmail.com> 于2026年4月10日周五 16:39写道：
   >>
   >>> 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
   

5. Re: Add missing CHECK_FOR_INTERRUPTS in autovacuum catalog scan loops

   Sami Imseih <samimseih@gmail.com> — 2026-04-11T20:10:42Z

   Hi,
   
   It was discussed [1] here if C_F_I is needed in these
   do_autovacuum/autovacuum_scores code paths, and it
   was decided not to add them.
   
   Also, at least on my tests with 100k evern with 1 million tables, I did
   not see a reason to do so. These are catalog scans that should
   happen quick enough, even in extreme cases, to not make
   this worthwhile.
   
   Others may have another opinion.
   
   --
   Sami
   
   
   [1] [https://www.postgresql.org/message-id/acwTxpz3Toxt0ty8%40nathan]