Re: Do I really need more than 1 rollback segment?

From: andrew_webby at hotmail <andrew_webby_at_hotmail.com>
Date: 11 Dec 2001 04:38:52 -0800
Message-ID: <f45d9b0.0112110438.414536d@posting.google.com>

Just as a 'further', I knew I'd picked up that "rule of thumb" somewhere and as in my previous post, it was when I posted my statspack report some time back.

From Johnathan Lewis:

"As already appreciate, your rollback segments seem to be much too big for activity shown, and the optimal is too high - little known rule of thumb, rollback segments should be as small and as few as possible to reduce redundant I/O. In your case the size of the rollbacks doesn't seem to have resulted in any significant I/O cost."

I'm sure his meaning was not to set them incredibly small as I appeared to be suggesting, but more to size them appropriately. Comments appreciated.

Andrew

"Howard J. Rogers" <dba_at_hjrdba.com> wrote in message news:<3c110a2a$0$29051$afc38c87_at_news.optusnet.com.au>...
> I agree with your disagree! Setting rollback segments 'as small as you can
> make them' is just plain daft, and setting optimal at all is equally mad.
> Optimal is there for those databases that don't have a full-time DBA, and as
> such it can be a useful 'light-weight management' tool. But in a
> properly-managed production database, it's an utterly lousy idea.
>
> Regards
> HJR
> --
> Resources for Oracle: http://www.hjrdba.com
> ===============================
Received on Tue Dec 11 2001 - 06:38:52 CST