Re: View with duplicate GROUP BY entries

Robert Haas <robertmhaas@gmail.com> writes:
> On Tue, Nov 21, 2017 at 12:05 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Yeah, we probably ought to make more of an effort to regenerate the
>> original query wording.  I do not think that forcing positional notation
>> is a suitable answer in this case, because it would result in converting
>> SQL-standard queries to nonstandard ones.

> Who cares?  The other end is presumptively PostgresSQL, because this
> is postgres_fdw.

No, you missed the context.  Yes, the original problem is in postgres_fdw,
and there indeed it seems fine to emit GROUP BY 1,2.  What Ashutosh is
pointing out is that ruleutils.c can emit a representation of a view
that fails to preserve its original semantics, thus causing dump/reload
problems that have nothing at all to do with FDWs.  And what I'm pointing
out is that we don't like pg_dump to emit nonstandard representations
of objects that were created with perfectly standard-compliant queries;
therefore emitting GROUP BY 1,2 isn't good if the query wasn't spelled
like that to begin with.
        regards, tom lane