Re: Tuning RMAN backup and recovery

From: Don Seiler <don_at_seiler.us>
Date: Mon, 3 Mar 2008 09:39:28 -0600
Message-ID: <716f7a630803030739s71e742f8sad5e4fdca0a73af9@mail.gmail.com>


I did have some follow-up questions regarding DBMS_STATS.GATHER_FIXED_OBJECT_STATS().

  1. We had noticed that, since gathering the fixed object stats, the time needed to perform a level 0 incremental backup dropped by around 40%. Is this not a coincidence?
  2. Is there any schedule or milestone upon which one should re-gather fixed object statistics?

Don.

On Mon, Feb 11, 2008 at 3:55 PM, Don Seiler <don_at_seiler.us> wrote:
> Just wanted to follow-up here as well. I finally decided to file an
> SR, and Oracle came back pretty quickly with Note 462879.1 [0], fixed
> in 10.2.0.4 and 11g. It seems that, in this bug, queries against
> v$rman_status table can take an extremely long time, and that table is
> queried for every datafile switch during RMAN DUPLICATEs
>
> Workarounds are to either set sesiion-level optimization to RULE
> based, or to gather fixed object statistics via
> dbms_stats.gather_fixed_objects_stats();.
>
> I've done the latter, but haven't had an opportunity to perform
> another restore as our development instances are needed until the next
> release in two weeks. I'll report back with results when I do.
>
> [0] https://metalink.oracle.com/metalink/plsql/f?p=130:14:6987901499320050620::::p14_database_id,p14_docid,p14_show_header,p14_show_help,p14_black_frame,p14_font:NOT,462879.1,1,1,1,helvetica
>
>
> --
> Don Seiler
> http://seilerwerks.wordpress.com
> ultimate: http://www.mufc.us
>

-- 
Don Seiler
http://seilerwerks.wordpress.com
ultimate: http://www.mufc.us
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Received on Mon Mar 03 2008 - 09:39:28 CST

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