RE: selectivity of predicates with LIKE

From: Boris Dali <boris_dali_at_yahoo.ca>
Date: Wed, 11 Jun 2003 10:40:05 -0700
Message-ID: <F001.005AF530.20030611102502@fatcity.com>

Thanks, KG

No, CURSOR_SHARING is not set (meaning it defaults to EXACT on both 8i and 9i)

No bind variables. The query given with ... LIKE 'LOVE%' is the real one

Yes, I can try setting _LIKE_WITH_BIND_AS_EQUALITY.

One additional piece of info - we don't have OPTIMIZER_INDEX_* parameter set on eigher one (I should re-read Tim's excellent paper). It would probably be a safer bet to change "supported" parameters first (after understanding what is different in 9i that is), but I am not sure what effect it might have on the rest of the app.

Cheers,
Boris.

K Gopalakrishnan <[EMAIL PROTECTED]> wrote: > By any chance are you using CURSOR_SHARING parameter
> in your 8i version?
> I think the default selectivity of 5% is used while
> costing the like
> operator and with the binds (and with an underscore
> parameter which
> I think defaults TRUE) it is treated as equality .
>
> If not you can set the underscore parameter
> _like_with_bind_as_equality to get the index
> costing.
>
> KG

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Author: Boris Dali
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Received on Wed Jun 11 2003 - 12:40:05 CDT

RE: selectivity of predicates with LIKE - diff between 8i and 9i