What type of trigger needs to be created?

You need to implement a virtual private database (vpd). In order to have the vpd functionality, a
trigger is required to fire when every user initiates a session in the database.What type of trigger
needs to be created?

A.
DML trigger

B.
System event trigger

C.
INSTEAD OF trigger

D.
Application trigger

Explanation:
System Event Triggers can be defined to fire at either at the schema level or database
level. You can create a trigger that is fired when a user connects to the
database. The triggering event in this case is LOGON. This trigger can be created either at the
database level or at the schema level. If the trigger is created at the database level, the trigger is
fired for all the users that connect to the database. If the trigger is created at the schema level,
the trigger is fired when the user that created the trigger connects to the database.
Incorrect Answers:
A: DML Triggers fire when a DML Operation is perform on a Table BEFORE OR AFTER (Trigger
Timing) the DML Event (INSERT, UPDATE or DELETE) on the TABLE.
C: INSTEAD OF TRIGGERS will fire on a view.D. Application trigger – Fires when a particular
event occurs in the application. Application triggersare developed using Oracle client-side tools,
such as Oracle Forms Developer.