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From: Tom Lane <tgl@sss.pgh.pa.us>
To: David Rowley <dgrowleyml@gmail.com>
cc: feasiblechart@gmail.com, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #19742: `INTERSECT` under a `UNION ALL` with an empty arm
 fails with "could not find pathkey item t"
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Comments: In-reply-to David Rowley <dgrowleyml@gmail.com>
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David Rowley <dgrowleyml@gmail.com> writes:
> I think the fix needs to be either don't remove redundant pathkeys for
> setop_pathkeys or use some other method to figure out which
> expressions to add in add_child_eq_member().

My own thoughts were along the lines of "don't ever assign pathkeys to
an AppendPath"; not sure if that's equivalent to your first idea.

In the long run I'd like to get rid of the varno-zero business
in favor of some less-magic representation; but that's clearly
not reasonable for v19.

			regards, tom lane