Re: Adding Index to Table may reduce performance of Some Select Statements ?

To receive any useful information, you will certainly need to provide additional details on your setup, or find someone more familiar with your Oracle to do it for you. The cases where I saw that an additional index slowed some select statements was generally when: - rule-based optimizing is used and the new index has low cardinality columns (few distinct values)
- cost-based optimizing is used, and the stats are not kept up-to-date - cost-based optimizing is used, and the indexed columns suffer from skewness, and no histograms are used.

Those are 3 examples, and is certainly not a complete list.

Daniel

srinikande_at_yahoo.com (srinik) wrote in message news:<95100be7.0401052035.6bccad52_at_posting.google.com>...
> Guy&#8217;s,
>
> Adding Index to Table may reduce performance of Some Select?
>
> Thanks in advance,
> Srini
Received on Tue Jan 06 2004 - 10:38:00 CST