Re: multi-column aggregates

Chris Kratz <chris.kratz@vistashare.com> writes:
> Thanks for the reply.  Yes, subselects would work very well and in some ways
> are more elegant then the hand waving we had to do to get the multi-column
> aggregates to work.

BTW, there is not any fundamental reason why we can't support aggregate
functions with multiple inputs.  I looked at this not long ago and
determined that the major stumbling blocks would be
(1) trying to keep the code in nodeAgg.c from getting a lot more
complicated and hence slower for the single-input case;
(2) figuring out how to change the syntax for CREATE AGGREGATE.

It certainly seems doable if someone wants to spend time on it.

            regards, tom lane