RE: Histograms - SIZE clause & num_buckets anomaly

From: Wolfgang Breitling <breitliw_at_centrexcc.com>
Date: Mon, 02 Aug 2004 16:56:45 -0600
Message-Id: <6.1.0.6.2.20040802164626.0351e290@pop.centrexcc.com>

The "analyze ... delete statistics" is only in order to delete index statistics - which delete_{table|index}_stats do not do. That comment had nothing to do with the histogram creation.

 From my understanding, purely from reading the documentation, method_opt=>'for all columns size skewonly' should re-evaluate all columns for skewness and create histograms accordingly, regardless of whether statistics pre-exist or not.

method_opt=>'for all columns size repeat' should refresh existing histograms using the same number of buckets as the existing histogram.

At 02:58 PM 8/2/2004, you wrote:
>Wolfgang,
> How are you? Hope you're doing well.
>
>Just wondering, if I have a database where we already generated histograms
>on everything, will method_opt=>'for all columns size skewonly' delete the
>old histograms and just leave me with the ones that are skewed? Or do I
>have to delete statistics first, like your other post mentioned?
>
>"Also, in order to delete statistics I still use analyze because
>delete_table_stats doesn't delete index stats."
>
> I wanted to follow up with the "repeat" option or just not analyze
>at all.
>
> Thanks
> Larry

Regards

Wolfgang Breitling
Centrex Consulting Corporation
http://www.centrexcc.com

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Received on Mon Aug 02 2004 - 18:09:13 CDT