Post Processing Function

Purpose

The Post Processing Function masking format is a special masking option that enables you to use a custom function to further transform column values after they have been masked using some other masking formats. It takes the intermediate masked values as input and returns the final masked values. For example, you can use it for adding checksums or special encodings to the masked values. This masking option requires some level of coding skills.

Inputs

• Package Name (Optional): The name of the database package
• Function Name: The name of the database function

The database function has a fixed signature:

function post_proc_func (rowid varchar2, column_name varchar2, mask_value varchar2) 
return varchar2;

where:

• rowid is the row identifier of the row containing the value to be masked.
• column_name is the name of the column to be masked.
• mask_value is the value to be masked.

Supported Data Types

• Character
• Numeric
• Date

Characteristics

• Supports Double-Byte Characters: Yes
• Combinable: Yes
• Deterministic: Does not apply
• Reversible: Does not apply
• Uniqueness: Does not apply

Example

You can use Post Processing Function to add a comma or dollar sign to a value. Suppose that you mask a SALARY column by using the Random Number masking format. You can then apply the Post Processing Function masking format to the masked values to add a currency symbol, such as $.

RANDOM NUMBER [START:25000 END: 100000]
POST PROCESSING FUNCTION salary_post_processing 	    

To create the salary_post_processing function, your code might look like the following:

CREATE OR REPLACE FUNCTION 
salary_post_processing (rowid varchar2, column_name varchar2, mask_value varchar2) 
RETURN varchar2
IS
BEGIN
    RETURN ('$' || mask_value);
END;