Re: Tuning By cardinality Estimates

From: (wrong string) 조동욱 <ukja.dion_at_gmail.com>
Date: Fri, 6 Mar 2009 20:45:34 +0900
Message-ID: <43c2e3d60903060345s4450c7f5o880b7ccb6b775e82_at_mail.gmail.com>

Because Oracle's basic assumption is not realistic?

Would you post both results(plan statistics) of nested loops version and hash version?

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Dion Cho - Oracle Performance Storyteller

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On Fri, Mar 6, 2009 at 8:34 PM, hrishy <hrishys_at_yahoo.co.uk> wrote:

>
> Hi Bhavik
>
> Thanks for quick response,and correcting my understanding on the starts
> column.
>
> Having understood the starts column and the cardinality calculation my
> question then would be why oracle is not using Hash Join and prefers a
> Nested Loop join
> It takes almost 8 minutes to complete the query with nested loops.If i use
> a use_hash hint it completes in 2 minutes
>
> regards
> Hrishy
>
>
>
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

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Received on Fri Mar 06 2009 - 05:45:34 CST