Re: numeric precision when raising one numeric to another.

On Fri, 20 May 2005, Scott Marlowe wrote:

> On Fri, 2005-05-20 at 09:06, Stephan Szabo wrote:
> > On Fri, 20 May 2005, John D. Burger wrote:
> >
> > > I find all these statements about the near-uselessness of
> > > NUMERIC^NUMERIC to be pretty amazing. It's fine to say, "no one seems
> > > to be asking for this, so we haven't implemented it yet", but, c'mon,
> > > folks, Postgres gets used for more than "business cases".
> >
> > If people don't see the use of a function they aren't going to implement
> > it. In addition, there is a small, but non-zero cost to adding a
> > function/operator to the system (in the cost to maintain it at the very
> > least) and if the general belief is that the function or operator is
> > useless or nearly useless then it simply may not be worth adding.
>
> A couple of points.

> 1: How much time has been expended in the last 5 or so years
> "maintaining" the floating point exponentiation operator? Seriously. I

Probably pretty little or none, but wasn't there a binary incompatible
change in numeric in that time?

> I could be wrong, and would be unoffended to be proven so, but I don't
> think I am. I think that argument is just hand waving.

It simply means that the value necessary to overcome it is very small. I'd
even argue that in this case, the value is probably higher than the cost.

> 2: How many people who DO work with large exponents and need arbitrary
> precision have looked at postgresql, typed in "select 3^100" got back
> 5.15377520732011e+47, and simply went to another piece of software and
> never looked back? We don't know. And the attitude that it seems
> useless to me so it must be useless to everybody else isn't going to
> help attract people who do things that seem esoteric and strange to you,
> but are important to them.

As a note, I don't think it's useless. I simply think the argument that
anything that can be included should is invalid. I could make
equivalent arguments for a whole lot of things and that's when the cost
argument starts making more sense.