A wet-pipe system is usually considered appropriate in computer rooms.

Assume a schedule consists of consistent transactions that execute in an isolated fashion except for one transaction that performs a single update that is lost (as in Figure 18.2). Showthat the final state of the database satisfies all integrity constraints but nevertheless is incorrect.

What will be an ideal response?

Which of the following statements are true?

a. A class should describe a single entity and all the class operations should logically fit together to support a coherent purpose. b. A class should always contain a no-arg constructor. c. The constructors must always be public. d. The constructors may be protected.