when the control break of the aggregate has fewer columns than 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, . . . , Ck) with an expression of the form AGG(AGG(C0)) OVER(PARTITION C1, C2, . . . , Ck), where each C is a column, where n is a number of columns in th