Question

A relation in which every non-key attribute is fully functionally dependent on the primary key and which has no transitive dependencies is said to be in:
1. BCNF
2. 2NF
3. 3NF
4. 4NF

Answer 1

Correct Answer - Option 3 : 3NF

1 NF

A relation R is in first normal form (1NF) if and only if all underlying domains contain atomic values only.

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.

Example: A → B, B → C , A → C here A is key and relation is in  2NF but A → B, B → C , A → C is transitive

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. Hence Option 3 is the correct answer.

BCNF

A relation R is in Boyce-Codd normal form (BCNF) if and only if every determinant is a candidate key.