In article <957084104.14440.0.nnrp-01.9e9864e7_at_news.demon.co.uk>,
"Mark" <mark_at_mark-it.demon.co.uk> wrote:
>
> Hi,
>
> Hope this is the appropriate NG for this...
>
> How does Oracle store number columns internally? For example, if a
table
> has a column of NUMBER(20), does each number require 20 bytes (one
byte per
> decimal digit), or is it stored as an internal binary representation
(8
> bytes?). Are there optimum NUMBER sizes that correspond to native
machine
> word sizes (16 bit, 32 bit etc.)
>
> Thanks
>
The Oracle datatypes are documentated in the Concepts manual and the
Application Developers Guide. Oracle stores all numberic column
definitions, float, integer, number(10,2), etc... as number which is
represented internally as a form of scientific notation. The storage
space formula is in the Concepts manual but is something like 1 byte
for the exponent + ( floor(digits/2) + 1) the mantissa + 1 byte for the
sign, but this is only required if the value is negative.
--
Mark D. Powell -- The only advice that counts is the advice that
you follow so follow your own advice --
Sent via Deja.com http://www.deja.com/
Before you buy.
Received on Sun Apr 30 2000 - 00:00:00 CDT
