From: Tom Lane <tgl@sss.pgh.pa.us>
To: Richard Guo <guofenglinux@gmail.com>
cc: Swirl Smog Dowry <swirl-smog-dowry@duck.com>,
        pgsql-bugs@lists.postgresql.org
Subject: Re: pg_get_viewdef() produces non-round-trippable SQL for views with USING join on mismatched integer types
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Comments: In-reply-to Richard Guo <guofenglinux@gmail.com>
	message dated "Fri, 27 Feb 2026 17:13:52 +0900"
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Date: Fri, 27 Feb 2026 10:21:43 -0500
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Richard Guo <guofenglinux@gmail.com> writes:
> I am on the fence about whether this fix is safe to back-patch to v18.

I don't think we have a lot of choice.  The cases where it makes a
difference are pretty broken.  Fortunately, I think these cases
are rare.  JOIN USING combining two different-type columns has got
to be an edge-case usage, and I think it likely doesn't matter much
in other cases.

> However, this fix will only apply to newly created views.  Users who
> have existing views affected by this bug will have to recreate them
> after upgrading to get the corrected pg_get_viewdef output.

Yeah :-(.  What's really annoying is that probably people will not
notice until they try to upgrade to v19, and by then recreating
the view correctly might be difficult.  But I'm not seeing a way
to smooth their path.

			regards, tom lane