Optimizer Plan's Cost

Hi Listers,

      I have one doubt regarding optimizer plan. would u please rectify them. Lets say I have a query like this

select * from foo where foo100=:b1 order by foodate;

The plan might be like this

Operation                                            Step#            Cost        
Select Statement                                   4                    24            
    Sort (order by)                                    3                   24
        foo table access                             2                   22
          fooidx index (range scan)              1                     1

Now what would be the cost of this plan. would it be the aggregate of all four operations that is 24+24+22+1=71 or would it be just of first operation i.e. 24 or what? Please clarify this. thanks regards,
Fahd

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