The schema of the Student Registration System includes the number of current registrants and a list of registered students in each course.

a. What integrity constraint relates this data?
b. Howmight a registration transaction that is not atomic violate this constraint?
c. Suppose the system also implements a transaction that displays the current
information about a course. Give a nonisolated schedule in which the transaction
displays inconsistent information.

a. The number of students on the list equals the number of current registrants
b. It might increment the number but crash before it appends to the list, and the
increment might not be rolled back
c. The display transaction takes a snapshot between the increment and the append