RE: Index help

From: Wolfgang Breitling <breitliw_at_centrexcc.com>
Date: Mon, 26 Jul 2004 09:50:56 -0600
Message-Id: <6.1.0.6.2.20040726094628.03568f20@pop.centrexcc.com>

Actually because the column is so "badly" (why is that bad?) skewed, the index is an excellent choice for all but the dominant value - provided the CBO a) knows about the skewed data distribution through either a histogram or through dynamic sampling
b) re-evaluates the access plan for each predicate value, which may not be the case if you are using bind variables

At 09:35 AM 7/26/2004, you wrote:
>If we go back to the original post with the Query then there are 3 columns
>referenced in the WHERE clause. It may still be possible to improve the
>query by building an index on those other columns. So far all the
>discussion has been on IDA3A5 which because it is badly skewed is not a good
>overall index choice.

Regards

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

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Received on Mon Jul 26 2004 - 10:49:50 CDT