Changing the function parameters for a specified column

There are several ways in which you can change an existing redaction policy. In this recipe and the next one, you will:

• Change the function parameters for a specified column (the a_tbl_partial policy, which you created in the recipe Creating a redaction policy when using partial redaction)

• Add a column (commission_pct in the hr.employees table) to the redaction policy EMP_POL (you defined it in the Creating a redaction policy when using random redaction recipe)

Also, it is possible to remove column from the redaction policy, alter the policy expression, and modify the type of redaction for a specified column.

You concluded that the  a_tbl_partial redaction policy doesn't satisfy the requirements for your application anymore because it redacts first four digits with 0 and leading zeros are not displayed in the application. You decide to alter the a_tbl_partial policy. You want all digits to be displayed and to have them redacted with some...