Database - The Relational Model and Normalization - Discussion

1NF
It should only have single(atomic) valued attributes/columns.

2NF
It should be in the 1NF.And, it should not have Partial Dependency

3NF
It is in the 2NF. And, it doesn't have Transitive Dependency.

BCNF
It is in 3NF. and for every functional dependencyX->Y, X should be the super key of the table.

For 4NF
The realtionship must be in 3NF, and there will not be any multivalued dependancy.

5NFA
It is in 4NF and it cannot be decomposed into any number of smaller tables without loss of data

At relation is said to be 4th normal form if it is in BCNF and there is no multivalued dependency.

If,

A drives B and.
A drives C.
But C and B are not linked.

Answer should be 3NF NORMAL FORM.

4NF requires multi dependency right? How can a relation which is in BCNF be in 4NF? A 4NF relation can be in BCNF right?

I think its right answer is 3NF for 4NF multivalued dependency required.

What is meant by descriptive attribute?

Ephram, if there is a there is a telephone no. As attribute and the subscriber has more than 1 no. Than it is called as multi valued hence ignoring such problem and also data redundancy problem normalization is used.

If it is in the BCNF form means, it is already in the 1st, 2nd and 3rd normal forms. Means, without fulfill all the requirements of 1st, 2nd, 3rd normal forms it won't go for BCNF.

And, 4th normal form will comes after the BCNF. So, BCNF no need to fulfill the requirements of 4th NF.

Can you please tell how to figure out that the relation is in which normal form?

If the relation is in BCNF that itself says that it is in the 4NF OR BCNF because it don't any partial or transitive dependencies.