Re: optimal size for rollback

One last question I hope.
What is the different between having a cron job shrinking the rollback and letting oracle does it automatically by setting optimal? If shrinking a rollback segment to its optimal size increases the chances of getting ora-1555, I am sure having a cron job to do it will have the effect.
I am sorry if I am being a pain but I need to understand this last bit.

Thanks everyone!

rgds
Daud

"Howard J. Rogers" <howardjr2000_at_yahoo.com.au> wrote in message news:<3d81e650_at_dnews.tpgi.com.au>...
> That's what dbms_job or cron is for.
>
> Optimal is only slightly worse as an idea than PCTINCREASE.
>
> Any time Oracle does anything for you automatically, there's a price to pay:
> and the price is performance.
>
> Don't set optimal.
>
> Period.
>
> (Or full stop, depending on your longitude).
>
> Regards
> HJR
>
>
> "Daud" <daud11_at_hotmail.com> wrote in message
> news:f0bf3cc3.0209130205.2cd2db2_at_posting.google.com...
> > Hi
> >
> > I have been reading quite a bit about rollback segments and I kinda
> > agree that setting optimal size is not quite a good idea. That shows
> > that a dba has not done his job to find out what the correct size of
> > the rollback segment should be.
> > This is what I am thinking of doing and let me know if it does not
> > make sense.
> >
> > initial 1M
> > next 1M
> > minextents 6
> > optimal 6M
> >
> > The reason I want to set optimal is because occasionally I have some
> > big jobs that cause a rollback segment to grow. However, I do not want
> > to have to manually go in and re-set its size once the jobs are done.
> > So, I thought setting optimal will take care of it. What do you
> > experts think?
> >
> > rgds
> > Daud
Received on Sat Sep 14 2002 - 19:53:20 CDT