Re: Re bitmap index

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Wed, 24 Nov 1999 19:16:01 -0000
Message-ID: <943471166.24761.2.nnrp-12.9e984b29@news.demon.co.uk>

In fact, the greatest strength of bitmap indices comes from Oracle's ability to combine them, rather than the individual indices themselves.. There is an article with some interesting numbers on my web-site.

Jonathan Lewis
Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk

Brian Peasland wrote in message <383BF59F.CAB68D88_at_edcmail.cr.usgs.gov>...
>There is a problem with trying to use bitmap indexes on columns that
>have too low of a cardinality. If the cardinality is too low, it is
>better to do a full table scan. The "Gender" flag is a perfect example
>of a case where I normally wouldn't use a bitmap index. The reason for
>this is distribution and spread.
>
Received on Wed Nov 24 1999 - 13:16:01 CST