Re: Documentation says DECIMAL is floating-point but it is fixed-point

[Kloppenburg Ernst (FV/FLI) *]

On Mon, Aug 20, 2001 at 06:39:55 -0600, Benjamin David Hildred wrote:
> On Mon, Aug 20, 2001 at 02:00:29PM +0200, Kloppenburg Ernst (FV/FLI) *  wrote:
> > On Mon, Aug 20, 2001 at 06:06:22 -0600, Benjamin David Hildred wrote:
> > > On Mon, Aug 20, 2001 at 11:08:47AM +0200, Ernst Kloppenburg wrote:
> > > > >Description:
> > > >         with DECIMAL the number of digits before and after the decimal
> > > > point is fixed. Thus it should be described in the documentation as a
> > > > fixed point number
> > > > >How-To-Repeat:
> > > the manual is correct. the number is stored internaly as a floating point number 
>with all of its benifets and drawbacks. formating information is only used when the 
>number is retrieved. if a number is stored in atable with more significant digets 
>than the coulum will alow, and the table is later restructured to show aditional 
>precision, the number will show mour preciosion. try it.
> > 
> > Hello,
> > 
> > did you maybe mix this up with "DOUBLE(M,D)"? DOUBLE is of course stored
> > as a float and M and D control the display at retrieval of a number.
> > 
> > For DECIMAL the manual says
> > 
> >     the number is stored as a string, using one character for each
> >     digit of the value. The decimal point and, for negative numbers,
> >     the `-' sign, are not counted in M (but space for these are
> >     reserved). If D is 0, values will have no decimal point or
> >     fractional part. The maximum range of DECIMAL values is the same
> >     as for DOUBLE, but the actual range for a given DECIMAL column may
> >     be constrained by the choice of M and D.
> > 
> > I still think this sounds like *storing* in a fixed point format.
> > 
> > E. Kloppenburg
> > 
> sorry about the misinormation, I was using a verry old manual. recent versions do 
>have a bcd number types. checking the most recent manual (online) in section 6.2.1: 
>Numeric Types, in paragraph two it says explecetly that they are not folating point. 
>So what was the complaint?

In the overview at the beginning of section 6.2 (before the start of
6.2.1), DECIMAL is described as 
  "An unpacked floating-point number...". 
This is the statement I find misleading. I think the term "fixed-point
number" should be used here.

Of course, in 6.2.1 things become very clear, but if you do not read
that far...

E. Kloppenburg 


-- 
Dr. Ernst Kloppenburg
Robert Bosch GmbH, Abt. FV/FLI
Tel. 0711/811-6739, BCN 9020-6739

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