Re: undo segments online causing performance problems.

  Do you have StatsPack snapshots for those times [as presented as an example in Note 301432.1] ? Or queries on V$SESSION_WAIT ?

At 08:41 PM Thursday, The Human Fly wrote:

>Basically, when transaction comes, we have flag called queue for
>different status and we see that the query is growing heavily for not
>process status, and when I go and check the alert.log file, exactly at
>the same time and second, oracle bring undo segs online. We have
>noticed this situation thrice comparing with undo segs online process
>and we determined the same.
>
>Note:301432.1 Subject: Performance Slowdown During Heavy Undo Segment
>Onlining
>
>We are exactly facing the same problem mentioned in this metalink note
>and as per Oracle Support advice, we also enable the event 10511, to
>prvent SMON taking undo segs. offline.

Hemant K Chitale
http://web.singnet.com.sg/~hkchital

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