Re: Column position

This is not true. If the last column in a row is null, no bytes at all are taken up. This has always been the case for Oracle.

Not sure how much of a performance impact one byte per row will have for your system though. Seems unlikely to be much.

Marc Perkowitz
MTP Systems Consulting

In a message dated 6/21/00 2:16:06 PM Central Daylight Time, rajagopalvr_at_excite.com writes:

<< Hi,  

   Either way, Oracle will still consume atleast 1 byte for storing    the null indicator value. Does not really matter where this column    is positioned.  

 Regards
 Rajagopal Venkataramany  

 On Tue, 20 Jun 2000 09:33:18 -0800, ORACLE-L_at_fatcity.com wrote:  

> Hi all
>
> I have a table defined as:
>
> my_table:
> prt_name VARCHAR2(10) NOT NULL,
> imp_date DATE NOT NULL,
> atr_type CHAR(5) NOT NULL,
> atr_data VARCHAR2(512)
>
> There are millions of records in this table
> I would like to add another column:
> exp_id VARCHAR2(10)
>
> I can do it using the ALTER TABLE command and the column will
> end up as the last in the table or I can recreate the table, putting
> the column in different position, and reload the data. The column
> like atr_data is VARCHAR2 and can contain nulls. The table is just
> an example, I have number of tables to which I need to add another
> column.
>
> Would there be a performance difference depending on the column
> position?
>
> Thanks
>
> Witold
>
> --
> Author: Witold Iwaniec
> INET: wiwaniec_at_novalistech.com
>
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Received on Thu Jun 22 2000 - 12:50:04 CDT