Correct Answer - Option 3 : Every relation in BCNF is also in 3NF
The correct answer is "option 3".
CONCEPT
Normalization is used to minimize redundancy from a set of relations.
It is used to organize data effectively in the database.
Normal forms are used to reduce redundancy from the database.
Third Normal form: A relation is said to be in third normal form if it is in 2NF & there must not exist any transition dependency.
Also, it must satisfy these properties:
1. For the function A → B, A should be a super key.
2. B should be a part of a key attribute or prime attribute i.e. B should be a part of a candidate key.
BCNF: A relation is said to be in Boyce-Codd normal form (BCNF) if it is in 3NF & must satisfy this property:
1. For the function A → B, A should be a super key.
EXPLANATION:
Option 1: FALSE
Any relation in BCNF must be in 3NF.
Option 2: FALSE
A relation R is in 3NF if every non-prime attribute of R is fully functionally dependent on every key of R but this does not guarantee transitive dependency.
Option 3: TRUE
Every relation is BCNF must be in 3NF.
Option 4: FALSE
Any relation can be in both BCNF & 3NF if it satisfies the condition of BCNF.
Hence, the correct answer is “option 3”.
