April 2010
Intermediate to advanced
468 pages
10h 31m
English
Imagine that you're eagerly anticipating a parcel to be delivered to your home. You keep looking out your window to see if the mail man has arrived. Besides being extremely inefficient, you can't concentrate on your work, and you get a sore neck from all that craning. Wouldn't it be nice if the mail man could call you on your phone when the parcel was delivered? Many scenarios in the workplace are similar. You have to keep checking every day to see if your colleague has already created that sales quotation. Your e-mail program has to keep checking the mail server to see if you have any new e-mail.
Similarly, in the database, your application has no idea of knowing if data has changed. ...