ISRO2018-41

Question

For a database relation $R(a,b,c,d)$ where the domain of $a,b,c$ and $d$ include only atomic value, only the following functions dependencies and those that can be inferred from them hold

$a\rightarrow c$

$b\rightarrow d$

The relation is in:

1. First normal form but not in second normal form
2. Second normal form but not in third normal form
3. Third normal form
4. None of the above

Comments

Original Source of this question: GATE 1997

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

Answer 1

option a

partial dependecy so it is in 1NF.

Answer 2

answer: A

Answer 3

1^st atomic means it is in 1NF

2^nd

(ab)+ = abcd (so, ab is candidate key)

prime attributes are : a,b 

partial dependencies are: a → c,b → d

therefore, it is not in 2NF

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