The Oracle and different Oracle tools are supplied with the product-specific packages which help you to build the PL/SQL-based applications. For illustration, the Oracle is supplied with a lot of utility packages, a few of that are highlighted below.
The Package DBMS_STANDARD gives language facilities which help your application interact with the Oracle. For illustration, the procedure raise_application_error issue a user-defined error messages. In that way, you can report the errors to an application and evade returning the unhandled exceptions.
The Package DBMS_ALERT use the database triggers to alert an application when the definite database values change. The alerts are asynchronous (i.e., they operate separately of any timing mechanism) and transaction based. For illustration, a company may use this package to update the value of its investment portfolio as the new stock and bond quotes arrive.