There are times when I want my database to be able to talk to the outside world, rather than the other way around. Let's explore some scenarios where this ability would come handy before implementing a solution using Ingres RDBMS and Perl. You can see the result in action and the code is available to replicate it with any RMDBS.
For example, the database ought to alert an external entity:
A. in a Drugstore, whenever an item's stock decreases beyond a fail-safe limit
B. in a Post Office, whenever an item arrives and its barcode is scanned
C. in a Hospital, whenever a patient is diagnosed with a condition
D. in a Hospital, whenever a patient is admitted into the Hospital or is prescribed medicine