Re: Why Adding "+0" Make A Query Run Faster

I'm wondering if vector_id is declared as a varchar2 in one table and as a number in the other ... then, the +0 would perform an implicit to_number conversion BEFORE hitting the index.

Just a thought.

pagesflames_at_usa.net (Dusan Bolek) wrote in message news:<1e8276d6.0206192335.7645c14a_at_posting.google.com>...
> "Roman Mirzaitov" <rmirzaitov_at_kt.kg> wrote in message news:<aergf6$91iti$1_at_ID-127142.news.dfncis.de>...
> > Hi,
> >
> > adding 0 to column means disabling indexes on that column in RBO
> > environment.
> > That's why you got different explain plans.
>
> No that can't be a reason, because:
>
> a) He's not using RBO, he's using CBO (on partitioned table, that's
> the only way).
> b) In both of explains for that column is used INDEX RANGE SCAN, which
> doesn't seem to me like "disabling indexes".
>
> The change between two of them is that CBO decided to use NESTED LOOP
> using some partitions instead of HASH JOIN through all partitions.
>
> --
> _________________________________________
>
> Dusan Bolek, Ing.
> Oracle team leader
>
> Note: pagesflames_at_usa.net has been cancelled due to changes (maybe we
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Received on Thu Jun 20 2002 - 12:24:41 CDT