This exercise is a variation of Exercise 18. Consider the following functional dependencies prevailing over the relation schema CLASS (Student, Subject, Teacher):
{Student, Subject} †’ Teacher
Teacher --/--> Subject
Subject --/--> Teacher
{Student, Teacher} --/-> Subject
a. What do these rules mean in words? Are all these rules necessary? If not, explain which are not needed.
b. Is the following sample data consistent with these rules? Why or why not?

c. Does this version of CLASS satisfy the requirements of BCNF? Is it free of modification anomalies triggered by undesirable functional dependencies? Is it free of modification anomalies altogether?

Transcribed Image Text:

Student Smith Smith Jones Jones Subject Math Physics Math Physics Teache White White Green White