Re: Oracle SQL question

From: Phil Preen <obiwan-preen_at_maytheforcebewithyou.co.uk>
Date: Tue, 11 Jan 2000 13:01:03 -0000
Message-ID: <947595832.921212@red.parallax.co.uk>

<gweilo97_at_my-deja.com> wrote in message news:85d21k$bcg$1_at_nnrp1.deja.com...
>
> > the /*+ ..... */ indicates the force to use a certain method and
> > another hint is to use a bitmap index on columns where there are just
> > a few possible distinct values like sex has probably three: M,F and
> > null, it will increase speed.
>
> Thanks for this. What happens if the index referred to doesn't exist?
> Performance problems?
>

The original programmer presumably added the hint for a good reason (usually to optimise for performance). If the index has been removed you probably need to re-optimise the query and/or re-create the index. I suggest you try find out why the index was removed, and why whoever removed it didn't re-optimise all the queries which used it. Alternatively run some performance tests, and if it is acceptable, don't worry about it. Received on Tue Jan 11 2000 - 07:01:03 CST