VPD implementation—outline and components
The development steps of VPD implementation is demonstrated in the flowchart as follows:
Creation of an application context: The application context is a collection of variables whose values, once set, remain the same and are available in the same session. The variables are known as attributes. Each session accessing the same application context attributes can have different values.
Create the context key and value: Create the trusted program to set the context using
DBMS_SESSION.SET_CONTEXT. During the creation of the context, Oracle does not verify the existence of the program being specified. It relies on the trust of the user to create and use a program with the same name to set the context attributes. Therefore, the program is referred to as trusted.Set the context key explicitly or through a Logon trigger: The context must be set for the whole session or just before each call. System-level Logon triggers are also capable of scheduling...
