From: Tom Lane <tgl@sss.pgh.pa.us>
To: Dean Rasheed <dean.a.rasheed@gmail.com>
cc: zwj <sxzwj@vip.qq.com>, pgsql-hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: bug report: some issues about pg_15_stable(8fa4a1ac61189efffb8b851ee77e1bc87360c445)
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Comments: In-reply-to Dean Rasheed <dean.a.rasheed@gmail.com>
	message dated "Wed, 21 Feb 2024 17:00:45 +0000"
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Date: Thu, 22 Feb 2024 11:20:54 -0500
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Dean Rasheed <dean.a.rasheed@gmail.com> writes:
> Attached is a patch that prevents UNION ALL subquery pullup in MERGE only.

I think that this is a band-aid that's just masking an error in the
rowmarking logic: it's not doing the right thing for appendrels
made from UNION ALL subqueries.  I've not wrapped my head around
exactly where it's going off the rails, but I feel like this ought
to get fixed somewhere else.  Please hold off pushing your patch
for now.

(The test case looks valuable though, thanks for working on that.)

			regards, tom lane