Test by Bikram | Databases | Test 2 | Question: 2

Question

The relation R (ABCDE) with FD set $\{AB \rightarrow CDE, \ A \rightarrow C, \ C \rightarrow D\}$ is in which of the following normal forms?

• A.  1NF but not in 2NF
• B.   in both 2NF and 3NF
• C.   in 3NF but not in BCNF
• D.   in BCNF

Answer 1

First, we need to find the candidate keys.

From the given functional dependencies, only $AB$ is the candidate key.

We have a partial dependency here,

$A \rightarrow C$

So, it is not in $2NF$.

Hence, option (A) 1NF but not in 2NF

Answer 2

C is not fully functionally dependent on candidate key AB because A-->C. so it is not in 2NF.So answer is A