Re: Rollback Segment Trouble

Thanks, Mark.

Arthur had replied directly to my e-mail with that question and I replied directly to his e-mail. I didn't see the ng posting until later.

mark.powell_at_eds.com wrote:

> In article <36e0d0b6.6002768_at_news.chaven.com>,
> amerar_at_unsu.com (Arthur Merar) wrote:
> >
> > Hello,
> >
> > I have a couple of questions revolving around rollback segments. Any
> > help would be appreciated.
> >
> > First, on Thursday I received a call that users were getting messages
> > of follback segments not being able to get any more extents. So, I
> > first extended all the rollback segments by 15 extents. That did not
> > help, so I extended the tablespace by 15, and that did not help
> > either. So, finally I shrunk all the rollback segments to optimal and
> > that worked.
> >
> > I used Desktop DBA to do some reverse engineering on the rollback
> > segment to see how it was built. Interesting.....although the Optimal
> > parameter was specified, there was no value. And, the Optimal column
> > in v$rollstat is NULL. Why is this?
> >
> > What is a good size for the optimal on a rollback segment? These are
> > short queries running against this database. Here is the code that
> > made all the rollback segments in my database:
> >
> > CREATE ROLLBACK SEGMENT RB01
> > TABLESPACE RBS
> > STORAGE (INITIAL 262144
> > NEXT 262144
> > MINEXTENTS 10
> > MAXEXTENTS 500
> > OPTIMAL )
> >
> > What should optimal be?
> >
> > Also, what should my normal response be when a rollback segment runs
> > out of room like that?
> >
> > Thanks for your help.
> >
> > Arthur
> > amerar_at_unsu.com
> >
> >
>
> Mr. Higgins posted a pretty good reply, but he never posted an answer to what
> to set your optimal setting to. Why not start with the smallest possible
> size which is your minextents (10) times your extent size (256k) and then
> monitor the extends, shrinks and aveshrink from v$rollstat.
>
> Mark D. Powell -- The only advice that counts is the advice that
> you follow so follow your own advice --
>
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Received on Mon Mar 08 1999 - 16:37:11 CST