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In-Reply-To: <4054709.1758895915@sss.pgh.pa.us>
From: David Christensen <david@pgguru.net>
Date: Fri, 26 Sep 2025 10:52:36 -0500
Message-ID: 
 <CAHM0NXib3ZpAkPypXS6coGrydWadp8NXHvSinOcGF+uOHJs+hQ@mail.gmail.com>
Subject: Re: [PATCH] GROUP BY ALL
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Peter Eisentraut <peter@eisentraut.org>,
 pgsql-hackers <pgsql-hackers@postgresql.org>,
	"David G. Johnston" <david.g.johnston@gmail.com>,
 Jelte Fennema-Nio <postgres@jeltef.nl>
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On Fri, Sep 26, 2025 at 9:12=E2=80=AFAM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Peter Eisentraut <peter@eisentraut.org> writes:
> > The initially proposed patch appears to have the right idea overall.
> > But it does not handle more complex cases like
> >      SELECT a, SUM(b)+a FROM t1 GROUP BY ALL;
>
> > (For explanation:  GROUP BY ALL expands to all select list entries that
> > do not contain aggregates.  So the above would expand to
> >      SELECT a, SUM(b)+a FROM t1 GROUP BY a;
> > which should then be rejected based on the existing rules.)
>
> I thought I understood this definition, up till your last
> comment.  What's invalid about that expanded query?
>
> regression=3D# create table t1 (a int, b int);
> CREATE TABLE
> regression=3D# SELECT a, SUM(b)+a FROM t1 GROUP BY a;
>  a | ?column?
> ---+----------
> (0 rows)

Agreed that this shouldn't be an error; added a similar test case to
v2 of this patch.

David