Re: Experiences with Automatic Undo Management

From: Connor McDonald <hamcdc_at_yahoo.co.uk>
Date: Mon, 27 Jan 2003 15:33:51 -0800
Message-ID: <F001.0053B989.20030127153351@fatcity.com>

Maybe I'm just a cynic but I view AUM as being akin the SAME disk layout policy. That is, (and this is subjective figures) it gives 90% optimal performance in about 90% of databases out there.

Since going to aum on a "significant" (read: reasonable number of users and workload) database I used to manage in the UK, I found aum gave ever so slightly increased undo figures in v$waitstat, but not really enough to discount it. Similarly, file IO was slight increased (which I have put down to its fairly aggressive nature of enforcing retention time).

One thing that is good about aum, is that it encourages people to never shut their databases (a policy I advocate strongly).

I would like to be able to have multiple undo tspaces simply as an aid to IO balancing

Cheers
Connor

• "Fink, Dan" <Dan.Fink_at_mdx.com> wrote: > This is more of a survey than a question about
  > problems.
  >
  > For those of you using automatic undo management,
  > what have been your
  > experiences, both good and bad. Are you also using
  > flashback query and what
  > are your experiences?
  >
  > Thank you for all the responses,
  >
  > Dan Fink
  >
  >
  

  ---

Connor McDonald
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email: connor_mcdonald_at_yahoo.com

"GIVE a man a fish and he will eat for a day. But TEACH him how to fish, and...he will sit in a boat and drink beer all day"

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Received on Mon Jan 27 2003 - 17:33:51 CST