Re: Tuning RMAN backup and recovery

  • From: "Don Seiler" <don@xxxxxxxxx>
  • To: oracle-l <oracle-l@xxxxxxxxxxxxx>
  • Date: Mon, 3 Mar 2008 09:39:28 -0600

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@xxxxxxxxx> 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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