Re: Oracle Lite 3.0 does not use indexes ?1?

From: Mohamad SALEH <msaleh_at_orsys.fr>
Date: Fri, 04 Sep 1998 16:17:40 +0200
Message-ID: <35EFF684.D7A6E5AC@orsys.fr>

hr_stoyanov_at_my-dejanews.com wrote:

> Hi folks,
> I observe very strange performance problems with Oracle Lite 3.0.6.2.4
> I have a big table (about 6 million records) and a simple query like this:
>
> SELECT population_80
> WHERE population_80>1000
>
> If you index population80 (via Oracle Navigator) it takes about 5 min to
> complete the query. However, if you drop the index - only one minute. Is that
> true that Oracle Lite uses indexes only for comparison "=" and not for "<" and
> ">" ?

Using indexes doesn't always mean better performance! If the majority of your rows in the example
has a value > 1000, then using the index will be poor. If you use the rule based optimizer approach
to execute the statement the index will be used even if it has poor performance result! Received on Fri Sep 04 1998 - 09:17:40 CDT