Re: Does Ref. Integrity help CBO ?

klabu wrote:
> 10gR2
>
> Does Ref. Integrity help CBO ?
> or maybe my Q should be: Does Statistics take RI into consideration ?
>
> So if say joining n tables....
> Does the fact that these tables have RI amongst them "help" CBO do a
> "better" job
> than if they just have PKs defined ?
>
>
> thanks, hope i'm making sense, I tried ;)
>
>

I don't know for sure, but my inclination is that a FK constraint by itself does not help the CBO. However, indexing the FK columns *may* help the join performance. If that is the case, it is the index and not the FK constraint that is providing benefit.

HTH,
Brian

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Brian Peasland
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