Re: datatype sizes
From: Guido Vrankar <guido_at_unit.de>
Date: 1996/08/29
Message-ID: <503uc7$dv9_at_dagobert.unit.de>#1/1
>>
>> Can anyone point me to a manual reference that gives the byte
>> requirements for each of the Oracle datatypes. I'm trying to estimate
>> the disk space requirements for a database. I've found the "higher
>> level" formulas that calculate the files size based on a row of a
>> given size. But they show NADA on how to calculate the row size.
>> Specifically, I need the size for a DATE and a NUMBER. I assume,
>> given that a NUMBER datatype can handle up to 32 significant digits,
>> it must be at least 16 bytes. (If I did my math corrrectly. <big ole
>> grin>)
>>
>> Thanks,
>>
>> Gary Shell
Date: 1996/08/29
Message-ID: <503uc7$dv9_at_dagobert.unit.de>#1/1
Brian P. Mac Lean wrote:
>gshell wrote:
>>
>> Can anyone point me to a manual reference that gives the byte
>> requirements for each of the Oracle datatypes. I'm trying to estimate
>> the disk space requirements for a database. I've found the "higher
>> level" formulas that calculate the files size based on a row of a
>> given size. But they show NADA on how to calculate the row size.
>> Specifically, I need the size for a DATE and a NUMBER. I assume,
>> given that a NUMBER datatype can handle up to 32 significant digits,
>> it must be at least 16 bytes. (If I did my math corrrectly. <big ole
>> grin>)
>>
>> Thanks,
>>
>> Gary Shell
> The SEPTEMBER/OCTOBER 1996 Oracle Magazine has an article on "Sizing > Tables and Indexes in Oracle7". Go to http:/www.oramag.com and become > a member. You will find this issue/article in the archive area. The > text contains PL/SQL code to calculate the size of an object based on > the variables you pass it.
You will also find some information in your Server Administration-Book
from Oracle (chapter 8 in the german version). It includes a nice table
with the characteristics of the datatypes. There is only one error in it:
It states that RAW-columns could take up to 2000 Bytes. At least in our
7.1.6.2 installation this is plain simple not true. We have up to 255
Bytes, quite a difference. Other documents tell about 255 Bytes, so it's
not so very important.
This source says a DATE has 7 Bytes and a NUMBER at most 21 Bytes (how much
you really use for fixed length numbers is unfortunately not told).
Guido
| Guido Vrankar UNIT Logistic Systems | | email: guido_at_unit.de voice-mail: ++49 2306 20215-33 | ----------------------------------------------------------------Received on Thu Aug 29 1996 - 00:00:00 CEST