From: Tom Lane <tgl@sss.pgh.pa.us>
To: Dilip Kumar <dilipbalaut@gmail.com>
cc: ilya.v.gladyshev@gmail.com, pgsql-hackers@lists.postgresql.org
Subject: Re: Segfault on logical replication to partitioned table with foreign
 children
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Comments: In-reply-to Dilip Kumar <dilipbalaut@gmail.com>
	message dated "Sun, 30 Oct 2022 15:16:01 +0530"
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Date: Sun, 30 Oct 2022 09:39:21 -0400
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Dilip Kumar <dilipbalaut@gmail.com> writes:
> Yes, this looks like a bug and your fix seems correct to me.  It would
> be nice to add a test case for this scenario.

A test case doesn't seem that exciting to me.  If we were trying to
make it actually work, then yeah, but throwing an error isn't that
useful to test.  The code will be exercised by replication to a
regular partitioned table (I assume we do have tests for that).

What I'm wondering about is whether we can refactor this code
to avoid so many usually-useless catalog lookups.  Pulling the
namespace name, in particular, is expensive and we generally
are not going to need the result.  In the child-rel case it'd
be much better to pass the opened relation and let the error-check
subroutine work from that.  Maybe we should just do it like that
at the start of the recursion, too?  Or pass the relid and let
the subroutine look up the names only in the error case.

A completely different line of thought is that this doesn't seem
like a terribly bulletproof fix, since children could get added to
a partitioned table after we look.  Maybe it'd be better to check
the relkind at the last moment before we do something that depends
on a child table being a relation.

			regards, tom lane