Let's say there is only room for one student in a course, and two people are seeking to sign up. What property of a database system makes it impossible for both students to be placed in the last open seat?

Let's pretend that your job entails inventory management for a popcorn manufacturer. Any establishment that doesn't have at least 15 boxes of caramel popcorn in stock must receive more of it each month. If you were to use a database to accomplish this, how would you go about doing so?

In your opinion, what are the most important benefits of using a database-driven methodology?