Composite sort keys are not currently allowed in the CUME_DIST function. You can use composite sort keys with any of the other
Elements of window-spec can be specified either in the function syntax (inline), or in conjunction with a WINDOW clause in the SELECT statement.
When used as a window function, you must specify an ORDER BY clause, you may specify a PARTITION BY clause, however, you can
not specify a ROWS or RANGE clause. See the window-spec definition provided in WINDOW clause.
For more information about using window functions in SELECT statements, including working examples, see Window functions.