Re: proposal: tuplestore, tuplesort aggregate functions

"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> Robert Haas <robertmhaas@gmail.com> wrote:
>> I suppose there could also be a bit of an ambiguity if you're working
>> with a type like int4 where the values are discrete steps.  Like, what
>> do you do with {1, 2}?

Hmm, good point.
> The same thing you do with the avg function?

avg's approach is not at all datatype-independent though.  If you're
willing to give up the idea of a polymorphic median() function, that
would probably be the thing to do.  If not, you need to take the left
or right one of the two central elements.
        regards, tom lane