Re: Tuning RMAN backup and recovery

From: Don Seiler <don_at_seiler.us>
Date: Tue, 4 Mar 2008 08:32:41 -0600
Message-ID: <716f7a630803040632s306761dfsffe1920a10ccf6cc@mail.gmail.com>


Taking away the following juicy nuggest:

  1. "Statistics on the dictionary tables will be maintained via the automatic statistics gathering job run during the nightly maintance window."
  2. "You only need to gather fixed objects statistics once for a representative workload and they are not updated by the automatic statistics gathering job."

Answers both my questions.

Thanks,
Don.

On Mon, Mar 3, 2008 at 1:05 PM, Greg Rahn <greg_at_structureddata.org> wrote:
>
> On 3/3/08, Don Seiler <don_at_seiler.us> wrote:
> > I've read a couple blog posts that say to gather fixed object stats
> > weekly, during normal business hours. Another page [0] also suggested
> > gathering dictionary stats as part of the same weekly process.
> >
> > Anyone have any thoughts?
> >
> > Don.
> >
> > [0] http://www.toadworld.com/Community/ExpertsBlog/tabid/67/EntryID/135/Default.aspx
> >
> >
> > On Mon, Mar 3, 2008 at 9:39 AM, Don Seiler <don_at_seiler.us> wrote:
> > > 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?
>
> I would recommend that you check out
> Upgrading from Oracle Database 9i to 10g: What to expect from the
> Optimizer
> http://www.oracle.com/technology/products/bi/db/10g/pdf/twp_bidw_optimizer_10gr2_0208.pdf
> This is discussed on page 7 & 8 (Statistics on Dictionary Tables &
> Statistics on Fixed Objects)
>
>
>
> --
> Regards,
>
> Greg Rahn
> http://structureddata.org
>

-- 
Don Seiler
http://seilerwerks.wordpress.com
ultimate: http://www.mufc.us
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Received on Tue Mar 04 2008 - 08:32:41 CST

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