Oracle Advanced PL/SQL Developer Professional Guide

VPD implementation—demonstrations

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 ...