System triggers : Trigger « Trigger « Oracle PL/SQL Tutorial

There are a number of events where you can set system triggers such as

ON LOGON, ON LOGOFF, ON STARTUP, ON DROP, ON TRUNCATE, and so on.

You can even track when any DDL command (CREATE, DROP, ALTER, and so on) was executed in the database.

You may place system triggers at the database level or schema level.

At the database level, triggers fire for each event for all users.

At the schema level, triggers fire for each event for a specific user.

28.2.Trigger
	28.2.1.	Triggers
	28.2.2.	System triggers
	28.2.3.	Creating a Trigger
	28.2.4.	Trigger Blocks
	28.2.5.	Trigger that output old value
	28.2.6.	DML Trigger Example
	28.2.7.	Firing a Trigger
	28.2.8.	The use of a trigger
	28.2.9.	INSERTING, DELETING and UPDATING Predicates
	28.2.10.	Reference current user name in trigger
	28.2.11.	Call raise_application_error to report an error in a trigger
	28.2.12.	Use cursor in trigger
	28.2.13.	Check the status of the trigger
	28.2.14.	Show errors for a trigger