UGC NET CSE | June 2013 | Part 3 | Question: 9

Question

For a database relation R(a, b, c, d) where the domains of a, b, c, d include only the atomic values. The functional dependency a $\rightarrow$ c, b $\rightarrow$ d holds in the following relation.

• A. In 1NF not in 2NF
• B. In 2NF not in 3NF
• C. In 3NF
• D. in 1 NF

Comments

Original Source of this question: GATE 1997

https://gateoverflow.in/2265/gate-cse-1997-question-6-9 

Answer 1

Candidate Key={a,b}

Given a,b,c,d all are atomic so relation in 1NF

Now,

$a\rightarrow b$

$c\rightarrow d$

Since here are partial dependencies,Hence it can't be in 2NF 

Hence,Option(A)In 1NF not in 2NF.

Answer 2

https://gateoverflow.in/2265/gate1997_6-9

Answer 3

Option A will be right option for it.

Bcz Ck will =ab

Now we can clealy see that a->b and b->d will be partial keys so it will not be in 2NF but it will be in 1NF.This is very very important point to keep into mind.