Re: Partitioning or BitMap-Index?

From: Howard J. Rogers <howardjr2000_at_yahoo.com.au>
Date: Thu, 13 Feb 2003 03:38:16 +1100
Message-ID: <pan.2003.02.12.16.38.16.119464@yahoo.com.au>

On Wed, 12 Feb 2003 04:17:53 +0000, Christian Hartmann wrote:

> Hi there,
>
> I have 8.1.7 database and a table with a column with values of 0 and 1.
>
> The column is used in every sql-statement against the table.
>
> For this low cardinality I wonder wheter a bitmap-index or a partitioning
> is the best way to improve the performance of this table.
>
> Any suggestion?

Is the column subject to change, ie DML? If so, run away from bitmap indexes. A single bitmap index on a table is also not the world's most useful thing -their power really comes from the combination of lots of them.

If you partition by this column of 1s and 0s, you are (presumably) going to end up with two large slabs of data. Not sure if that would buy you very much in terms of performance... it depends so much on what other things are going on in your SQL. On the other hand, it wouldn't be difficult to test.

Regards
HJR
>
> Regards,
>
> Christian Hartmann
Received on Wed Feb 12 2003 - 10:38:16 CST