TRIGGERS

Triggers: Triggers are used to stop Invalid Transactions which are performed by the End User                   to improve Business Rules.

• A Trigger is a special class of stored procedure and is defined on tables or views.
• Triggers are executed automatically when an update, insert or delete statement is issued against a table or a view.
• Triggers are powerful tools that are used to enforce the database rules automatically while you modify data.
• A Trigger is an SQL procedure that initiates an action when an event(insert,delete or update) occurs.
• Triggers are stored in & managed by the Oracle database and are used to maintain the referential integrity of data by changing the data systematically.
• A Trigger cannot be called or executed,Triggers are fired automatically.

The Triggers are used for the following purpose:

1. T o generate the resulting data automatically.
2. To enforce complex integrity constraints security authorizations business rules.
3. To avoid invalid Transactions.
4. To enforce the referential integrity across nodes in a distributed database.
5. To provide transparent event logging and advanced auditing data modifications.
6. To maintain synchronous table replicates and check the status of the table access.