RE: RMAN Sizing - Anomaly?

From: Bellows, Bambi (Comsys) <"Bellows,>
Date: Mon, 16 Feb 2009 13:51:50 -0600
Message-ID: <AD0CB572A820AB4E8E52ABD38950FD3605EF16E7_at_a0001-xpo0150-s.hodc.ad.allstate.com>

Yes. (and that EOF after the semicolon is, indeed, on a separate line... I don't know why the email reformatted it that way, but, mysteries abound.)

-----Original Message-----
From: Niall Litchfield [mailto:niall.litchfield_at_gmail.com] Sent: Monday, February 16, 2009 1:49 PM
To: Bellows, Bambi (Comsys); oracle-l_at_freelists.org Subject: Re: RMAN Sizing - Anomaly?

Is backup optimization on?

On 2/16/09, Bellows, Bambi (Comsys) <bbel5_at_allstate.com> wrote:
>
> Friends --
>
> I'm at a loss to explain why two nearly identical scripts -- one to
> backup the database only and one to backup the database plus
archivelog
> should have this particular sizing anomaly. First, here are the
> scripts...
>
> 1)
> $ORACLE_HOME/bin/rman <<EOF
> connect target;
> connect catalog $RMANID/$RMAN_at_$RMAN_CATDB;
>
> backup as compressed backupset database;
> EOF
>
> And
>
> 2)
> $ORACLE_HOME/bin/rman <<EOF
> connect target;
> connect catalog $RMANID/$RMAN_at_$RMAN_CATDB;
>
> backup as compressed backupset database plus archivelog;
> EOF
>
> Now the results...
> Database only: 48 minutes - 39.1GB
> Database plus archivelog: 63 minutes - 15.2GB
>
> Why should the database plus archivelog be 40% smaller than the
database
> without? I've run this test a bunch of different times, sometimes
> setting the incremental level to 0, sometimes not; sometimes running
the
> db+arch first, sometimes second. But consistently, the db+arch is
> appreciably smaller than the db without. How come?
>
> Thanks!
> Bambi.
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

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Niall Litchfield
Oracle DBA
http://www.orawin.info

--
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Received on Mon Feb 16 2009 - 13:51:50 CST