GATE | GATE-CS-2016 (Set 1) | Question 33

A database of research articles in a journal uses the following schema.

(VOLUME, NUMBER, STARTPGE, ENDPAGE, TITLE, YEAR, PRICE) 

The primary key is (VOLUME, NUMBER, STARTPAGE, ENDPAGE) and the following functional dependencies exist in the schema.

(VOLUME, NUMBER, STARTPAGE, ENDPAGE) -> TITLE
(VOLUME, NUMBER)                     -> YEAR
(VOLUME, NUMBER, STARTPAGE, ENDPAGE) -> PRICE 

The database is redesigned to use the following schemas.

(VOLUME, NUMBER, STARTPAGE, ENDPAGE, TITLE, PRICE)
(VOLUME, NUMBER, YEAR) 

Which is the weakest normal form that the new database satisfies, but the old one does not?

(A) 1NF
(B) 2NF
(C) 3NF
(D) BCNF


Answer: (B)

Explanation: Old relation has functional dependency : Volume, Number -> Year as partial dependency. So it does not follow 2NF.
But, there is no partial dependency in the New relation and so it satisfies 2NF as well as 3NF.

Therefore, 2NF is the weakest normal form that the new database satisfies, but the old one does not.
Option (B) is true.

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