We will demonstrate two ways of VPD implementation. While the first method is simple association of a policy, the second demonstration uses an application context for the same. Before we get into the actual implementation, let us have a look at the employees table. Notice the explain plan for the SELECT query:
/*Select the EMPLOYEES table data*/ SQL> SELECT * FROM employees /
/*Generate the explain plan for the above query*/ SQL> EXPLAIN PLAN FOR SELECT * FROM employees; Explained. /*Display the explain plan*/ SQL>SELECT * FROM TABLE(dbms_xplan.display);
We will take up the same scenario of employees where the employee often viewed other department's salaries and argued with their management. As a result, management took a heavy step by limiting the access in its host department only.