Configure value cascades as similar value columns and define one of the columns as the driving column. If you assign a rule to the driving column, Test Data Manager assigns the rule to all the columns in the group. For example, you configure employee_num column in one table and EmpID in another table as similar value columns. Define employee_num as the driving table. When you assign a data masking rule to employee_num, EmpID receives the same masking rule. The columns in a value cascade must be the same type.