"Brendan Jurd" <direvus@gmail.com> writes:
> I noticed a peculiarity in the default postgres aggregate functions. min()=
> ,
> max() and avg() support interval as an input type, but stddev() and
> variance() do not.
> Is there a rationale behind this, or is it just something that was never
> implemented?
Is it sensible to calculate standard deviation on intervals? How would
you handle the multiple components? I mean, you could certainly define
*something*, but how sane/useful would the result be?
regards, tom lane