Re: Crashes on a partition whose concurrent detach never finished

Hi,

On Wed, Nov11, 2026 at 05:06 PM shveta malik wrote:
> On Wed, Nov 11, 2026 at 1:05 PM Zhijie Hou <houzhijie22(at)gmail(dot)com> wrote:
> > Since we are considering whether to push 0001 first, I reviewed it
> > and have few suggestions:
> >
> > 1. We can remove the am_partition variable completely and simply check
> > "ancestors" in the subsequent code, to be consistent with
> > RelationBuildPublicationDesc.
> >
> > 2. The test can be simplified to cover only the decoding crash (since
> > the subscriber side is not touched by this patch), which saves
> > buildfarm test time. In addition, we can move the test into the
> > existing isolation test to speed it up further.
> >
> > I have attached a top-up patch for 0001 with these changes. Feel
> > free to merge it if it looks good.
>
> I agree with the changes. Few concerns:

Thanks for reviewing.

>
> It would be better to show in the additional steps that
> pg_inherits.inhdetachpending is true before we actually try
> pg_logical_slot_get_binary_changes.

I checked that no existing tests (either for DETACH CONCURRENTLY or
otherwise) refer to the inhdetachpendin in their test cases, and since
our test basically tests the DETACH behavior as well, I think it's fine
to skip testing this.

>
> Also I feel it would make more sense to create-pub with default
> publish_via_partition_root rather than publish_via_partition_root=true
> for PG19's testcase.

Changed as suggested.

After some analysis, I think creating slots in src/test/isolation/
wouldn't be stable, since some buildfarm animals may run the main
regression tests under wal_level=minimal. I also didn't find slot
creation in the main isolation tests. So I chose to put the test in
test_decoding/concurrent_ddl_dml.spec, which has precedent for creating
slots with pgoutput under test_decoding tests, so it can be acceptable.

I'm helping to merge the changes into 0001 and preparing patches for all
branches, hoping to close this item soon.

--
Best Regards,
Zhijie Hou