Creating different policy functions

The purpose of a policy function is to return a predicate that will be applied in WHERE clause of the statement (except for INSERT operation). In this recipe, you'll create several simple policy functions, based on different business and security requirements.

Getting ready

To complete this recipe, you'll need to create the table hr.emp_vpd_test, insert several values into that table, and create several users (in our case, susan, joel, emma, maja, and zoran already exist).

Figure 3 - A test table

If you won't use the same data as shown in Figure 4, then keep in mind to accordingly make changes in the How to do it section and the rest of the recipes in this chapter.

Figure 4 - Test data in the table hr.emp_vpd_test

How to do it...

1. Connect to the database as a user who has appropriate privileges (for example, user maja):

   $ sqlplus maja
   

2. Create a policy function that satisfies this condition: The user susan can't access data in a table (for example, hr.emp_vpd_test...