Re: sql query not use index

From: <johnbhurley_at_sbcglobal.net>
Date: Mon, 9 Mar 2009 11:38:15 -0700 (PDT)
Message-ID: <7efdb617-1399-4089-92cd-ed4264a3a536_at_l16g2000yqo.googlegroups.com>

On Mar 9, 2:11 pm, sydneypue..._at_yahoo.com wrote:
> Hello Guys,
>
> I was asked yesterday a project manager what sort of query will not
> use an index?
> What sort of index ? I asked
> say a varchar(256) ?
> A badly written regex. I responded.
> OK thanks.
>
> Now I am worried I have given a misleading or wrong response!
> Can anyone help me out with a better answer?
>
> TIA
>
> Syd

Almost all of my regular indexes of character fields don't go longer than 20/30 characters. What is the point exactly of indexing 256 characters unless it is a text index you are talking about here.

Might be a better idea to get some sample queries from the project mananger against this field than to take stabs in the dark at least that will give you a working idea of what and how they are thinking they want to use that index for. Received on Mon Mar 09 2009 - 13:38:15 CDT