RE: Impact on running rman

  • From: "Randy Johnson" <randyjo@xxxxxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Wed, 27 Jun 2007 20:27:28 -0500

We may be getting off topic a bit. I think the original question was "is it
ok to run backups or restore verify during business hours" (paraphrased).
That said I am enjoying hearing everyon's points on rate vs duration.  


From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Robert Freeman
Sent: Wednesday, June 27, 2007 1:28 PM
To: Jared Still
Cc: oracle-l@xxxxxxxxxxxxx
Subject: RE: Impact on running rman

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
Oracle Consultant/DBA/Author
Principal Engineer/Team Manager
The Church of Jesus Christ of Latter-Day Saints
Father of Five, Husband of One,
Author of various geeky computer titles
from Osborne/McGraw Hill (Oracle Press)
Oracle Database 11g New Features Now Available for Pre-sales on!
Sig V1.1 

-----Original Message-----
From: Jared Still [mailto:jkstill@xxxxxxxxx]
Sent: Wednesday, June 27, 2007 11:59 AM
To: robertgfreeman@xxxxxxxxx
Cc: oracle-l@xxxxxxxxxxxxx
Subject: Re: Impact on running rman

On 6/26/07, Robert Freeman <HYPERLINK
"mailto:robertgfreeman@xxxxxxxxx"robertgfreeman@xxxxxxxxx> 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

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