Re: undo header and buffer busy wait

On Fri, 15 Feb 2002 20:46:42 GMT,
u518615722_at_spawnkill.ip-mobilphone.net (Mike F) wrote:

>Thanks for Howard J. Rogers and Mark D Powell's help.
>
>But after I make our rollback segments 10 times bigger, we are still
>get the same undo header wait event, it did not show any improvment.
>
>Our database is collecting data through robot, each second we have
>about 30 rows comming, and we are using auto committing.
>
>Actually I seldom see any transaction using rollback segment, because
>it commits so quickly. But why we are getting undo header contention?
>
>Any thoughts?
>
>thanks
>
>
>

Because you are committing every individual transaction. Having committed your transaction the subsequent transaction needs to be set up and acquire a rollback segment. Obviously that new transaction would need to read the rollback segment header.

Regards

Sybrand Bakker, Senior Oracle DBA

To reply remove -verwijderdit from my e-mail address Received on Fri Feb 15 2002 - 15:07:22 CST