Re: index usage in not like

On 18 February 2010 11:55, AI Rumman <rummandba@gmail.com> wrote:
> "Not like" operation does not use index.
>
> select * from vtiger_contactscf where lower(cf_1253) not like
> lower('Former%')
>
> I created index on lower(cf_1253).
>
> How can I ensure index usage in not like operation?
> Anyone please help.
>

How many rows do you have in your table?  If there are relatively few,
it probably guesses it to be cheaper to do a sequential scan and
calculate lower values on-the-fly rather than bother with the index.

Thom