6. PGT Computer Science Question Discussion

6. PGT Computer Science Question Discussion

If every non-key attribute is functionally dependent on the primary key then the relation will be in

A. 1NF

 

B. 2NF

 

C. 3NF

 

D. 4NF

 

It Should be in 2NF.

 

According to the definition of 2NF and 3NF

 

2 NF – A relation R is in second normal form (2NF) if and only if it is in 1NF and every non-key attribute is fully dependent on the primary key.

Note that it does not put any restriction on the non-prime to non-prime attribute dependency. 

For Example

A--->B, B--->C , A--->C here A is key and relation is in  2NF.

Here A is Primary Key and every non key attributes i.e. B and C fully dependent on A

But here B--->C is also a functional dependency which voilate 3NF

 

3 NF – A relation R is in third normal form (3NF) if and only if it is in 2NF and every non-key attribute is non-transitively dependent on the primary key.

 

So Answer Should be 2NF