Question

Consider a relation R with 5 attributes M, O, N, E, Y. You are given the following dependencies: M-> N O -> M Y -> E NM ->Y Its candidate keys are {( O)}.

1. Which of the following is a prime attribute for the relation R? _________________

i.M

ii.E

ii.O

iv. All attributes of the relation R are prime attributes

2. Which of the following is true about the given functional dependencies in the relation R? ______________

i.M -> N is a Not So Bad FD

ii. Y -> E is a Very Good FD

iii.NM -> Y is a Not So Bad FD

iv. O -> M is a Very Good FD

3. Which of the following is the normal form of the relation R? _____________

i.First normal form

ii.Second normal form

iii.Boyce-Codd normal form

iv. Third normal form

Answer 1

Consider a relation R with 5 attributes M, O, N, E, Y. You are given the following dependencies: M-> N O -> M Y -> E NM ->Y Its candidate keys are {( O)}.

1. Which of the following is a prime attribute for the relation R? _________________
Answer:-----------
iii). O, because M, N, E, Y are non-prime attributes ( Because ,These are not part of candidate key).

2. Which of the following is true about the given functional dependencies in the relation R? ______________
Answer:-----------
iv. O->M is a very good FD.

3. Which of the following is the normal form of the relation R? _____________
Answer:-----------
​​​​​​​ii). Second normal form, Because M->N, Y →E and NM →Y dependencies are violating 3NF properties, These are transitivity dependencies(Transitivity dependencies means, non-prime attribute ---> non-prime attribute).