when the control break of the aggregate is the same as the longest control break of the order list of control breaks, and the aggregate of the expression is of the form AGG(C0), replacing the expression AGG(C0) OVER (PARTITION BY C1, C2, . . . , Cn) with an expression of the form AGG(C0), where each C is a column and where n is the number of columns in the longest control break.