I'm constantly finding, in the database that I'm developing/supporting,
b-tree indexes on columns with low-cardinality. I generally re-create said
index as a bitmap; however I'd like to go through the entire db and identify
these cases proactively. Is there a way to determine the cardinality of an
index's columns via the dictionary? Also, what recommendations do you have
for determining the cardinality percentage that indicates when a bitmap
should be used? 10%? 20%?
--
Please see the official ORACLE-L FAQ: http://www.orafaq.net
--
Author: Jeremy Pulcifer
INET: Jeremy.Pulcifer_at_kadiri.com
Fat City Network Services -- 858-538-5051 http://www.fatcity.com
San Diego, California -- Mailing list and web hosting services
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Received on Fri Dec 20 2002 - 13:56:26 CST
