Re: ORDER/GROUP BY expression not found in targetlist

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