From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
cc: pgsql-hackers@lists.postgresql.org, Andrew <pgsqlhackers@andrewrepp.com>
Subject: Re: pg_dump versus hash partitioning
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Comments: In-reply-to Robert Haas <robertmhaas@gmail.com>
	message dated "Wed, 01 Feb 2023 16:52:30 -0500"
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Date: Wed, 01 Feb 2023 18:14:36 -0500
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Robert Haas <robertmhaas@gmail.com> writes:
> On Wed, Feb 1, 2023 at 4:12 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> That being the case, I don't think moving the goalposts for hash
>> function stability is going to lead to a workable solution.

> I don't see that there is any easy, clean way to solve this in
> released branches. The idea that I proposed could be implemented in
> master, and I think it is the right kind of fix, but it is not
> back-patchable.

You waved your arms about inventing some new hashing infrastructure,
but it was phrased in such a way that it wasn't clear to me if that
was actually a serious proposal or not.  But if it is: how will you
get around the fact that any change to hashing behavior will break
pg_upgrade of existing hash-partitioned tables?  New infrastructure
avails nothing if it has to be bug-compatible with the old.  So I'm
not sure how restricting the fix to master helps us.

			regards, tom lane