Re: BITMAP INDEXES....WHAT IS THE SCOOP

From: Troy Fruetel <Troy_Fruetel_at_connects.com>
Date: 1997/11/10
Message-ID: <647i90$sk5$1@news3.mr.net>#1/1

>>Where are these things be best used..?<<

On tables that are read-only, or very infrequently updated. Best used on very large tables. Also use if the result set returned by most queries on the particular table return thousands of rows.

Mike wrote in message <3463F47A.F2F12257_at_anywhere.com>...
>We have been experimenting with BMP indexes on our ORACLE 7.3 database
>running on Solaris.
>
>The reults are very odd...sometime the indexes appear to be smaller for
>columns with high cardinality, sometimes the opposite. Replacing the
>BTrees with BMP has also had mixed impact.
>
>Can anyone speak with any authority on this subject:
>
>Where are these things be best used..?,
>
>Why do the sizes vary so much..?
>
>If you have any information that might be of help...please repley to
>QMICK_at_PIPELINE.COM
>
>Thanks.
>
>
>
>
Received on Mon Nov 10 1997 - 00:00:00 CST