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PL/SQL commit [message #65652] Tue, 23 November 2004 04:25 Go to next message
Bharath Kumar ,V
Messages: 18
Registered: February 2004
Junior Member
Hi,

I've a Procedure to make a data transfer between two tables. with-in this procedure I'm using cursor loop, in this process I did commit for every record successfully transfer. In this regard the performence is very very slow. can any one suggest me instead of commit I can use savepoint? or I make intervel to commit the records.

TIA

Bharath
Re: PL/SQL commit [message #65653 is a reply to message #65652] Tue, 23 November 2004 05:02 Go to previous messageGo to next message
Mahesh Rajendran
Messages: 10694
Registered: March 2002
Location: oracleDocoVille
Senior Member
Account Moderator
DO Not commit for every reecord.
ONE commit after all the records are processed Or at the end of loop will HELP.

or to commit in intervals use a mod function, please refer here

http://www.orafaq.net/msgboard/plsql/messages/12341.htm

As told , COMMIT inside a loop is always harmful
Re: PL/SQL commit [message #65655 is a reply to message #65652] Tue, 23 November 2004 18:22 Go to previous messageGo to next message
Dipankar Bhattacharya
Messages: 4
Registered: October 2003
Junior Member
U can commit after every 100-500 records, based on record size. If u do not commit at intervals ur RBS will be affected, causing serious performance issues, also committing after each record in a loop is not recommended .
Re: PL/SQL commit [message #65657 is a reply to message #65655] Tue, 23 November 2004 20:08 Go to previous messageGo to next message
Frank
Messages: 7880
Registered: March 2000
Senior Member
"your RBS will be affected, causing serious performance issues"
This is only true if there are more processes accessing the same data. If there is only 1 process, how does extending Rollbackspace affect performance ??
Re: PL/SQL commit [message #65658 is a reply to message #65657] Tue, 23 November 2004 21:34 Go to previous messageGo to next message
dipankar
Messages: 8
Registered: March 2004
Junior Member
Please clarify if you mean that if rollback segment is getting filled up , and it is not cleared by committing , it won't slow the process , and also if it is saturated, how will further processing take place ? thanx in advance Frank
Re: PL/SQL commit [message #65659 is a reply to message #65655] Wed, 24 November 2004 03:15 Go to previous messageGo to next message
Mahesh Rajendran
Messages: 10694
Registered: March 2002
Location: oracleDocoVille
Senior Member
Account Moderator
It is a true fact that frequent commit frees the Rollback segments ( undo segment).
But when rollback segments are freed 'pre-maturely' that leads to an ora-1555.
for every commit, more redo information is generated in redo buffer and 'force' cleared and is put in a queue to
be written to an OS file.
Committing based on count of records is Totally flawed ( to some extent in very certain cases,
committing based on TIME is much favoured).

Frequent commit will NOT reduce ANY RESOURCE CONSUMED.

>>>If u do not commit at intervals ur RBS will be affected, causing serious performance issues

The solution here is to size the RBS correctly, not committing frequently.

Please have a look here and see what Thiru says regarding
the process that happens FOR EVERY COMMIT

[Updated on: Fri, 18 February 2005 23:32]

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Re: PL/SQL commit [message #65664 is a reply to message #65658] Thu, 25 November 2004 20:25 Go to previous message
Frank
Messages: 7880
Registered: March 2000
Senior Member
If your RBS is full, you might hit an ORA-01555. This has nothing to do with performance.
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