Re: Do we need multiple forms of the SQL2003 statistics aggregates?

I wrote:
> There is room to argue that the numeric-arithmetic version would be
> worth having on the grounds of greater precision or range, but it's a
> big chunk of code and the public demand for the functionality has not
> exactly been overwhelming.

> Comments?

Since no one's even bothered to respond, I take it there's insufficient
interest in the numeric versions of these aggregates.  I've committed
just the float8 versions.

I added some very trivial regression tests, which we'll have to keep an
eye on to see if they have any portability problems.  We may need to
back off the number of displayed fraction digits to get them to pass
everywhere.

If anyone wants to do better tests, feel free...
        regards, tom lane