Question

Relation R has eight attributes ABCDEFGH. Fields of R contain only atomic values. 

F = {CH → G, A→BC, B→ CFH, EA, F→ EG} 

is a set of functional dependencies (FDs) so that F is exactly the set of FDs that hold for R

1. How many candidate keys does the relation R have? 

(A) 3 

(B) 4 

(C) 5 

(D) 6

2. The relation R is 

(A) in INF, but not in 2NF 

(B) in 2NF, but not in 3NF 

(C) in 3NF, but not in BCNF 

(D) in BCNF

Answer 1

1. (B) 4

Candidate keys are AD, BD, ED and FD

2. (A) in INF, but not in 2NF

A → BC, B → CFH and F → EG , are partial dependencies. 

Hence it is in 1NF but not in 2NF