Re: Purpose of rscale/dscale in NUMERIC?

Tom Lane wrote:
> 
> Jan Wieck <JanWieck@Yahoo.com> writes:
> > Tom Lane wrote:
> >> What is the reason for maintaining separate rscale and dscale values in
> >> numeric variables?
> 
> > You need to carry around a decent number of digits when you divide
> > already. Exposing them in a manner that numericcol(15,2) / 3.0 all of
> > the sudden displays 16 or more digits isn't much more intuitive. But
> > carrying around only 2 here leads to nonintuitively fuzzy results on the
> > other hand.
> 
> Certainly you need extra guard digits while you do the calculation.
> What I'm wondering is why the delivered result would have hidden digits
> in it.  If they're accurate, why not show them?  If they're not accurate
> (which they're not, at least in the case I showed) why is it a good idea
> to let them escape?

So we need them in the calculation, and if it's a nested tree of
function calls, they have to travel around too. What do you think is a
good place to kill these critters then?


Jan

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