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What is Normalization..?How many types are there.?

>> Sunday, October 10, 2010


Normalization:

Normalization is a design technique which helps to design the relational database.
Normalization is essentially a two step process that puts data into tabular form by removing redundant data from the relational tables.

Normalization has been divided into following types.

1.First Normal Form (1NF): A Relational table all column values are atomic.It means that it contains no repeating values.

(or)

A Relational table should not be any multivalued column.

2.Second Normal Form (2NF) : A Relational table is in second normal form if it is in First Normal form and every Non-Key Column is fully dependent on PrimaryKey.

(or)

The table should be in 1NF and every non key column must fully functional dependent on primaryKey.

3.Third Normal Form (3NF): A Relational table is in third Normal Form (3NF) if it is already in 2NF and every non-key column is non transitive dependent upon its primary key.

(or)

The table should be in 2NF and every non-key column should not be any transitive dependencies.

4.Boyce Codd Normal Form (BCNF) : The Relational table is in BCNF if it is already in 3NF and every non key column should not be overlapping between candidate keys.

(or)

The table should be in 3NF and the columns should not be overlapping between any candidate keys.

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