Message Oracle QSM-02138 - agg(expr) requires correspondng agg(expr*expr) function

ERRORagg(expr) requires correspondng agg(expr*expr) function
CAUSEThe capability in question is not supported when the materialized view uses certain aggregate functions but omits an invocation of that same aggregate function on the square of the same argument.
ACTIONAdd an invocation of the same aggregate function on the square of the same argument (that is, the argument multiplied by itself).