RE: How to know the stats is corrupted

From: <breitliw_at_centrexcc.com>
Date: Wed, 01 May 2013 08:25:26 -0600
Message-ID: <20130501082526.vo9ag5628scsso4o_at_webmail.telushosting.com>

One of the problems of moving from analyze to dbms_stats in 9i was that analyze table by default also analyzed the indexes. dbms_stats.gather_table_stats did not ( by default ). If you didn't pay attention to that fact you ended up with fresh table and column statistics but old index statistics from the last analyze - or no index statistics at all. Conflicting information from table and index statistics can lead to a plethora of problems for the optimizer.

On Wed, 1 May 2013 14:07:43 +0000, "Powell, Mark" <mark.powell2_at_hp.com> wrote: When we were on 9.2.x we got better results using analyze than we did using dbms_stats. I would use one of the other based on which produces the best overall results for your environment.
> When we upgraded to 10g we went with the Oracle provided statistics
> collection process. We had to tune only a couple of processes as a
> result of the upgrade.
>
>
> -----Original Message-----
> From: oracle-l-bounce_at_freelists.org
> [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of
> breitliw_at_centrexcc.com
> Sent: Tuesday, April 30, 2013 4:51 PM
> To: David Fitzjarrell; K R
> Cc: Oracle-L_at_freelists.org
> Subject: Re: How to know the stats is corrupted
>
> Yes, mixing analyze and dbms_stats.gatherxxx can cause problems. Use
> only dbms_stats. Also, export your stats before gathering. That way
> you can restore them if the new stats cause problems.

--
Wolfgang Breitling
Centrex Consulting Corporation


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Received on Wed May 01 2013 - 16:25:26 CEST