Re: less than, index and string

From: tmp123 <tmp123_at_menta.net>
Date: 1 Mar 2006 03:55:47 -0800
Message-ID: <1141214147.482466.131440@z34g2000cwc.googlegroups.com>

tmp123 wrote:

> My doubt is: which definition of an index for the table is the better
> one?. One using only CMIN? Combine CMIN and CMAX?

Hello,

Thanks to Mr.Powell and Mr.Fitzjarrell for their answers, and sorry for my delay (some other activities have became).

There are something that still I don't understand. The table contains a list of non-overlapping ranges, like:

CMIN CMAX

000-008-...
010-019-...
022-022-...

and the query is something like:

select * from ... where CMIN<=xxx and CMAX>=xxx;

in this case, it is the same to create and index for only column CMIN, or it has some advantages to create an index with CMIN and CMAX columns?

I ask that because I thought the second column in a two colums index is used only when there are several rows with the same value for the first column. And this is not the case.

Thanks again to everybody. Received on Wed Mar 01 2006 - 05:55:47 CST