Tatsuo Ishii wrote:
> > Jan Wieck wrote:
> > > > The hard limit is certainly no more than 64K, since we store these
> > > > numbers in half of an atttypmod. In practice I suspect the limit may
> > > > be less; Jan would be more likely to remember...
> > >
> > > It is arbitrary of course. I don't recall completely, have to
> > > dig into the code, but there might be some side effect when
> > > mucking with it.
> > >
> > > The NUMERIC code increases the actual internal precision when
> > > doing multiply and divide, what happens a gazillion times
> > > when doing higher functions like trigonometry. I think there
> > > was some connection between the max precision and how high
> > > this internal precision can grow, so increasing the precision
> > > might affect the computational performance of such higher
> > > functions significantly.
> >
> > Oh, interesting, maybe we should just leave it alone.
>
> So are we going to just fix the docs?
OK, I have updated the docs. Patch attached.
I have also added this to the TODO list:
* Change NUMERIC to enforce the maximum precision, and increase it
--
Bruce Momjian | http://candle.pha.pa.us
[EMAIL PROTECTED] | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
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Index: datatype.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v
retrieving revision 1.87
diff -c -r1.87 datatype.sgml
*** datatype.sgml 3 Apr 2002 05:39:27 -0000 1.87
--- datatype.sgml 13 Apr 2002 01:26:54 -0000
***************
*** 506,518 ****
<title>Arbitrary Precision Numbers</title>
<para>
! The type <type>numeric</type> can store numbers of practically
! unlimited size and precision, while being able to store all
! numbers and carry out all calculations exactly. It is especially
! recommended for storing monetary amounts and other quantities
! where exactness is required. However, the <type>numeric</type>
! type is very slow compared to the floating-point types described
! in the next section.
</para>
<para>
--- 506,517 ----
<title>Arbitrary Precision Numbers</title>
<para>
! The type <type>numeric</type> can store numbers with up to 1,000
! digits of precision and perform calculations exactly. It is
! especially recommended for storing monetary amounts and other
! quantities where exactness is required. However, the
! <type>numeric</type> type is very slow compared to the
! floating-point types described in the next section.
</para>
<para>
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