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From Rick Hillegas <rick.hille...@oracle.com>
Subject Re: Should the optimizer ever have a cost of "0.0"?
Date Tue, 27 Aug 2013 16:43:33 GMT
On 8/27/13 8:18 AM, Bergquist, Brett wrote:
> I am just wondering if while the optimizer is producing a plan if a cost of "0.0" should
ever be seen.  Thinking naively, it seems to me that all join plans and all access paths have
some sort of cost which should be greater than "0.0".   From my testing over the last few
days, when a plan comes up with a join such as "join T1 with T2" and the T1 cost is "0.0",
then this dominates the plan cost and even if T2's access path is going to be a table scan
of millions of rows, this plan might be chosen.   This just does not seem right to me.
>
>
>
>
Hi Brett,

A scan cost of 0 sounds like a bug to me.

Thanks,
-Rick

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