Re: rollback questions

"Paul Brewer" <paul_at_paul.brewers.org.uk> wrote in message news:<3e08b3ea_1_at_mk-nntp-1.news.uk.worldonline.com>...
> "Vince Laurent" <eAddict_at_yahoo.com> wrote in message
> news:7jte0v0vfhig104ti8cove5ajehj69rs0t_at_4ax.com...
> > On Sat, 21 Dec 2002 17:30:44 -0000, "Paul Brewer"
> > <paul_at_paul.brewers.org.uk> wrote:
> >
> > >How many concurrent transactions do you have?
> > SQL> select * from v$resource_limit where
> > resource_name='transactions';
> >
> > RESOURCE_NAME CURRENT_UTILIZATION MAX_UTILIZATION INITL_AL LIMIT_VALU
> > ------------- ------------------- --------------- -------- ----------
> > transactions 2 16 198 198
> >
> > >How many concurrent active sessions?
> >
> > That can vary. SAP assigns users in groups to 1 oracle process. I am
> > not sure what exactly the number is you are looking for here too. We
> > have so far maxed out at about 300 users on SAP at the same time.
> > Thats is not a 1 to 1 (SAP to Oracle) ratio.
> >
> > >How frequently is the database restarted?
> >
> > Once a week - until we get the mirroring/backup working...
> >
> > >Do you have overnight batch jobs running?
> > Yes. But I am unable to assign them to a specific rollback segment
> > since the user/transaction is masked by SAP.
> >
> > >What type of system is this (OLTP, DW, mixed)?
> >
> > OLTP would be the best description.
> >
> > Thanks for your help!
> > Vince
> >
> Then it sounds to me that your initial assessment is reasonable; reduce the
> number of segments to maybe 8, but increase the size of each to maybe 100
> mb.
> You are getting far to many extends.
>
> Let me know how this goes.
>
> Regards,
> Paul

Vincent, to answer your question how the HWM can be larger than the segment size: I would expect that optimal is set. See v$rollstat.

How large are you extents? I would think you should have 2M to 5M extents based on the average active statistics you posted.

HTH -- MArk D Powell -- Received on Tue Dec 24 2002 - 17:10:03 CST