Re: Bitmap Index, when use it?
Date: Fri, 1 Feb 2008 04:24:36 -0800 (PST)
On Jan 29, 12:50 am, Cassiano <cassianorol..._at_gmail.com> wrote:
> I've a table wich 6 milions of rows, and this table have one column
> "TYPE" char(2).
> This column is used to descript the type of the row.
> This column have 35 distict values and is frequently used in "where"
> I think this is a good column to create an Bitmap index? It's true? or
> 35 distict values is so much to bitmap indexes?
The biggest problem with bitmap indexes
is if the columns being indexed suffer frequent updates. If that is not the case then 35 distinct values should pose no problem whatsoever, abstracting any bugs. Note that I said "update". That is different from "insert" or "delete". Received on Fri Feb 01 2008 - 06:24:36 CST