As another example, consider a user making a booking over the Web. It is
possible that the database system or the application server crashes just after the
booking transaction commits. It is also possible that the network connection to
the user is lost just after the booking transaction commits. In either case, even
though the transaction has committed, the external write has not taken place.
To handle such situations, the application must be designed such that when the
user connects to the Web application again, she will be able to see whether her
transaction had succeeded or not.