Oracle-L: Which method is more efficient

From: Rodrigues, Bryan <BRodrigues_at_elcom.com>
Date: Wed, 28 May 2003 07:49:49 -0800
Message-ID: <F001.005A44B6.20030528074949@fatcity.com>

Hello everyone,

I have a question for the group of which method is more efficient.

To set the stage my company has a process to load part changes from vendors into the tables in an 8.1.7.4 Oracle database with archiving on and this database has a standby database at disaster recovery site, so nologging is not an option.

There is a discussion going on as to which method is more effective for updating the information in a table. In looking at effectiveness, I am looking at reducing the amount of redo information produced and having the database do the least amount of work.

Method 1 is to update the information only for the fields that have changed, 1 field at a time.
Method 2 is to update the information for all the fields in the record whether they have changed or not, 1 record at a time.

The size of the record is 1843 bytes and the distribution of field sizes: 2 fields varchar2(240).
1 field varchar2(150)
15 fields varchar2(50)
1 field varchar2(3)

2 fields varchar2(20)
4 fields varchar2(40)
3 fields varchar2(1)
2 fields varchar2(25)

2 fields number(10,2)
1 field number(13,2)
1 field number(1)
1 field number
1 field varchar2(6)
1 field number (17,2)
1 field varchar2(4)
3 fields that are date.

In the past couple of months the average number of fields changed per record was 3 to 4 fields per record.

Thanks for your help,

Bryan Rodrigues
Oracle DBA
Elcom, Inc.

--

Please see the official ORACLE-L FAQ: http://www.orafaq.net
--

Author: Rodrigues, Bryan
INET: BRodrigues_at_elcom.com

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------

To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Wed May 28 2003 - 10:49:49 CDT