Re: EXPLAIN PLAN differences

I may be going out on a limb here, but it could be because the data is different. You state that one database has a lot more data than the other and that statistics have been run. Since you have run statistics, I am assuming you are using the Cost Based Optimizer.

Since the amount of data is different, the statistics are different. The CBO uses statistics to choose the execution path, so I think it's within
reason to expect that different stat's lead to different explain plans.

HTH,
Patrick

"traceable1" <traceable1_at_hotmail.com> wrote in message news:8551d8c9.0206040837.364b51f7_at_posting.google.com

> If I do an execution plan on the same query on 2 different boxes, I
> get different results (Cost 26 vs 158). What does this mean? I'm
> trying to make the two databases behave the same, but they will not.
> One box has a lot more data than the other, but statistics have been
> run. I've checked the OPTIMIZER_MODE, what else could be causing the
> difference?
> They are both Oracle 8.1.7 on W2K.
>

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