Vik Fearing <vik.fearing@2ndquadrant.com> writes:
> On 18/08/2019 11:03, Peter Eisentraut wrote:
>> a UNION b
>> vs
>> a UNION CORRESPONDING b
> I have a WIP patch for CORRESPONDING [BY]. Is there any interest in me
> continuing it? If so, I'll start another thread for it.
CORRESPONDING is in the SQL standard, so in theory we ought to provide
it. I think the hard question is how big/complicated the patch would be
--- if the answer is "complicated", maybe it's not worth it. People
have submitted patches for it before that didn't go anywhere, suggesting
that the tradeoffs are not very good ... but maybe you'll think of a
better way.
regards, tom lane