Re: ORDER/GROUP BY expression not found in targetlist - Mailing list pgsql-hackers

From Tom Lane
Subject Re: ORDER/GROUP BY expression not found in targetlist
Date
Msg-id 26822.1464271975@sss.pgh.pa.us
Whole thread Raw
In response to Re: ORDER/GROUP BY expression not found in targetlist  (Andreas Seltenreich <seltenreich@gmx.de>)
Responses Re: ORDER/GROUP BY expression not found in targetlist  (Andreas Seltenreich <seltenreich@gmx.de>)
List pgsql-hackers
Andreas Seltenreich <seltenreich@gmx.de> writes:
> Peter Geoghegan writes:
>> It's surprising that SQL Smith didn't catch something with such simple
>> steps to reproduce.

> I removed distinct relatively early because it causes a large part of
> queries to fail due to it not finding an equality operator it likes.  It
> seems to be more picky about the equality operator than, say, joins.
> I'm sure it has a good reason to do so?

It's looking for an operator that is known to be semantically equality,
by virtue of being the equality member of a btree or hash opclass.
Type path has no such opclass unfortunately.  But when you write "a = b"
that just looks for an operator named "=".
        regards, tom lane



pgsql-hackers by date:

Previous
From: Andreas Seltenreich
Date:
Subject: Re: ORDER/GROUP BY expression not found in targetlist
Next
From: Nikolay Shaplov
Date:
Subject: Re: [PATCH][Documination] Add optional USING keyword before opclass name in INSERT statemet