DBMS_ALERT package

The DBMS_ALERT package provides a set of procedures for registering for alerts, sending alerts, and receiving alerts.

Alerts are stored in the DBMS_ALERT_EVENTS, DBMS_ALERT_REGISTERED, and DBMS_ALERT_SIGNALED tables which are created in your database when you register the package.

The DBMS_ALERT package includes the following system-defined routines.

Table 1. System-defined routines available in the DBMS_ALERT package
Routine name Description
REGISTER procedure Registers the current session to receive a specified alert.
REMOVE procedure Removes registration for a specified alert.
REMOVEALL procedure Removes registration for all alerts.
SIGNAL procedure Signals the occurrence of a specified alert.
SET_DEFAULTS procedure Sets the polling interval for the WAITONE and WAITANY procedures.
WAITANY procedure Waits for any registered alert to occur.
WAITONE procedure Waits for a specified alert to occur.

Usage notes

The procedures in the DBMS_ALERT package are useful when you want to send an alert for a specific event. For example, you might want to send an alert when a trigger is activated as the result of changes to one or more tables.