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RE: Impact on running rman

From: Robert Freeman <>
Date: Wed, 27 Jun 2007 12:27:36 -0600
Message-ID: <>

Thats the beauty of Duration, the backup is not discarded. Datafiles successfully backed up are considered backed up. During the next backup, those datafiles NOT backed up are prioritized first in that backup. Assuming you have the archived redo logs and all that, there is no risk to your database with the use of Duration, and you ensure that your backup window is met. You can use the partial parameter to avoid errors being reported if the backup window is exceeded and RMAN shutsdown the backup.

Duration can also be used like rate. If you know your backup takes 2 hours but you want to lessen the impact, you indicate a duration of, say 8 hours with the minimize load parameter. RMAN will then try to reduce the IO of the backup such that it will take 8 hours, thus reducing the IO overhead by 75%.

All in my Oracle Press Oracle Database 10g RMAN Backup and Recovery, or if you have Oracle Database 10g New Features it's in there too.

Pretty cool, eh? I believe (need to look this up to be sure) that rate is deprecated in 10g... still available, but not really supported anymore.


Robert G. Freeman
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  -----Original Message-----
  From: Jared Still []   Sent: Wednesday, June 27, 2007 11:59 AM   To:
  Subject: Re: Impact on running rman

  On 6/26/07, Robert Freeman <> wrote:     Oh RATE is SOOOO 9i!! :-)

    This is a 10g database so be looking at the duration parameter instead!! Talk all about this in chapter 16 of the 10g RMAN Book!!

  I suppose there are circumstances where you might choose DURATION.

  RATE however will ensure that your backups will finish, however slowly.

  DURATION will interrupt and discard a backup that does not complete within the specified window.
  Personally I can't think of a situation where I would want to do that.

  Why would you use it?

  Jared Still
  Certifiable Oracle DBA and Part Time Perl Evangelist

Received on Wed Jun 27 2007 - 13:27:36 CDT

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