Question

Consider a relation R (A, B, C, D, E, F, G, H), where each attribute is atomic, and following functional dependencies exist.

CH → G

A → BC

B → CFH

E → A

F → EG

The relation R is ______.

1. in 1NF but not in 2NF
2. in 2NF but not in 3NF
3. in 3NF but not in BCNF
4. in BCNF

Answer 1

Correct Answer - Option 1 : in 1NF but not in 2NF

The correct answer is option 1

Explanation:

Since attribute D is not a part of any FD, it must be a part of the candidate key.

AD+ = {ABCDEFGH}

BD+ = {ABCDEFGH}

ED+ = {ABCDEFGH}

FD+ = {ABCDEFGH}

CD+, GD+, and HD+ do not all the attributes. So, they can not be candidate keys.

Candidate keys are AD, BD, ED, and FD.

A → BC, B → CFH, and F → EG are partial dependencies. So, the relation is not in 2NF.

Hence the relation is in 1NF but not in 2NF.