From: Tom Lane <tgl@sss.pgh.pa.us>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
cc: Fabien COELHO <coelho@cri.ensmp.fr>, vignesh C <vignesh21@gmail.com>,
        Alvaro Herrera <alvherre@2ndquadrant.com>,
        Kyotaro Horiguchi <horikyota.ntt@gmail.com>, daniel@manitou-mail.org,
        peter.eisentraut@2ndquadrant.com, iwata.aya@jp.fujitsu.com,
        PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Subject: Re: psql - add SHOW_ALL_RESULTS option
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Comments: In-reply-to Tomas Vondra <tomas.vondra@2ndquadrant.com>
	message dated "Thu, 16 Jan 2020 18:48:21 +0100"
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Date: Thu, 16 Jan 2020 13:08:16 -0500
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Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
> This is one of the patches already marked as RFC (since September by
> Alvaro). Anyone interested in actually pushing it, so that it does not
> fall through to yet another commitfest?

TBH, I think we'd be better off to reject it.  This makes a nontrivial
change in a very long-standing psql behavior, with AFAICS no way to
get back the old semantics.  (The thread title is completely misleading
about that; there's no "option" in the patch as it stands.)  Sure,
in a green field this behavior would likely be more sensible ... but
that has to be weighed against the fact that it's behaved the way it
does for a long time, and any existing scripts that are affected by
that behavior have presumably deliberately chosen to use it.

I can't imagine that changing this will make very many people happier.
It seems much more likely that people who are affected will be unhappy.

The compatibility issue could be resolved by putting in the option
that I suppose was there at the beginning.  But then we'd have to
have a debate about which behavior would be default, and there would
still be the question of who would find this to be an improvement.
If you're chaining together commands with \; then it's likely that
you are happy with the way it behaves today.  Certainly there's been
no drumbeat of bug reports about it.

			regards, tom lane