When you configure multiple input fields to receive masked data from the same dictionary row, you need to decide which field to configure for substitution masking. With repeatable masking, select a column that uniquely identifies the source data. The Data Masking transformation uses the key field to determine if a row already exists in storage for repeatable masking.
When the source data has a primary key, you can configure the primary key column for substitution masking. Configure another column for dependent masking.
For example, if you mask employee data, you might configure the EmployeeID for substitution masking, and configure FirstName and LastName for dependent masking.
When you configure repeatable masking, the following rows receive different masked data:
EmployeeID FirstName LastName
111 John Jones
222 Radhika Jones
If you choose LastName as the key field for repeatable dependent masking, each row with the last name Jones receives the same mask data.