Answer all questions on test. Use back if necessary. No scrap paper will be grad

Question

Answer all questions on test. Use back if necessary. No scrap paper will be graded. Return you cheat sheet with test if using: Consider the F.R schema for the MOVIE database described by the figure below: Assume that MOVIE is a populated database. ACTOR is used as a generic term and includes actresses as well. Given the constraints shown in the ER schema, answer the following statements with True, False or Maybe. Justify each answer. There are no actors in this database that have no movies There are some actors who have acted in more than ten movies Some actors have done a lead role in multiple movies A movie can have only a maximum of 2 lead actors Every director has been an actor in some movie No producer has ever been an actor a producer cannot be an actor in some other movie

Explanation / Answer

a. TRUE (As we can see Actors have a full participation in PERFORM_IN , so there are no actors in database who have no movie.).

b. As we can see the cardinality of ACTORS-PERFORM_IN-MOVIE is m:n ,to be precise it is n movies ,so n can be anything 1,2,10 etc. So can't say its true or false ,therefore its MAYBE.

c. As we can see the cardinality of ACTORS-LEAD_ROLE is 2.so TRUE.

d.There is a relationship between ACTOR-ALSO_A_DIRECTOR-DIRECTOR so this can be true,but there is no full participation so it can be false also. Therefore MAYBE.

e.There is a relationship between ACTOR-ALSO_A_PRODUCER-PRODUCER so this can be true,but there is no full participation so it can be false also. Therefore MAYBE.

f.  As we can see the cardinality of ACTORS-PERFORM_IN-MOVIE is m:n ,to be precise it is m movies ,so m can be anything 1,2,10 etc. So can't say its true or false ,therefore its MAYBE.

g. Cardinality is a indicator of minimum and maximum bounds, as we can see in the ER diagram it is not sure weather its one or some other value. MAYBE

h.MAYBE(same reason as above)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.