Re: Rollback Segment Wrapping

On 9 Jan 2002 07:33:48 -0800, billiauk_at_yahoo.co.uk (billiauk) wrote:

>Is there any way we can get meaningful information from v$rollstat
>regarding wraps in the sense that the rollback segment recycles?
>
>There is a script available through Metalink that shows "wraps" as the
>ratio of writes/rssize, yet the view has a "wraps" column which I
>understood to be the number of extent switches.
>
>I'm trying to prove to our DBA's that we have too few rollback
>segments and that they are too small. We have a high number of waits
>and extends and several snapshot too olds, not all of which can be
>attributed to block cleanout.
>
>Thanks
>
>Adrian

Of course lousy code is a very common source for 'snapshot too old' messages. I would first ascertain you don't have lousy code in which you commit inside a loop updates to the table you are selecting from. My experience as a DBA is that developers always claim they never are at fault, and that this assertion quite often is NOT true.

Hth

Sybrand Bakker, Senior Oracle DBA

To reply remove -verwijderdit from my e-mail address Received on Wed Jan 09 2002 - 12:37:29 CST