On Thu, Aug 19, 2010 at 06:03:57PM -0400, Robert Haas wrote: > On Thu, Aug 19, 2010 at 5:53 PM, David Fetter <da...@fetter.org> wrote: > > On Thu, Aug 19, 2010 at 05:40:46PM -0400, Tom Lane wrote: > >> "Kevin Grittner" <kevin.gritt...@wicourts.gov> writes: > >> > Robert Haas <robertmh...@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. > > > > Whether the median needs to be in the sample is one question that > > doesn't really have a universal right answer. A separate > > question, also without a universal right answer, is whether the > > median needs to be in the same domain as the sample, int4 being > > the case above. > > > > We could just go with "whatever Oracle, DB2 and MS-SQL Server > > have," assuming it's the same thing, until something appears in > > the SQL standard. > > That's usually a sensible default, when in doubt. If nothing else, > it improves compatibility.
That's assuming we find such a thing, which I haven't yet. Trying to stay cheery, David. -- David Fetter <da...@fetter.org> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fet...@gmail.com iCal: webcal://www.tripit.com/feed/ical/people/david74/tripit.ics Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers