11.22. Email Notification with Triggers and Alerts
Database triggers can interface with database pipes and alerts. Figure 11-16 illustrates a model in which a database trigger posts a notification that a professor's salary has changed. This is a trigger that fires only from an update of the row. The trigger posts the alert. When the transaction commits, the signal is received by a second Oracle database connection. This connection is represented in Figure 11-16 as PROCESS_ALERTS, which has one purpose, to deliver email.
Figure 11-16. Trigger Email Notification.
Because PROCESS_ALERTS runs asynchronously, it has no impact on other database activity. ...