Date: Thu, 16 Jan 2020 18:05:52 -0300
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>,
	Fabien COELHO <coelho@cri.ensmp.fr>,
	vignesh C <vignesh21@gmail.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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On 2020-Jan-16, Tom Lane wrote:

> 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.

The patch originally submitted did indeed have the option (defaulting to
"off", that is, the original behavior), and it was removed at request of
reviewers Daniel Vérité, Peter Eisentraut and Kyotaro Horiguchi.

My own opinion is that any scripts that rely heavily on the current
behavior are stepping on shaky ground anyway.  I'm not saying we should
break them on every chance we get -- just that keeping them unharmed is
not necessarily a priority, and that if this patch enables other psql
features, it might be a good step forward.

My own vote would be to use the initial patch (after applying any
unrelated changes per later review), ie. add the feature with its
disable button.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services