Normalization

Normalization:

Normalization is a database design technique which organizes tables in a manner that reduces redundancy and dependency of data

1. First Normal Form
2. Second Normal Form
3. 3rd Normal Form
4. Boyce-Codd Normal Form (BCNF)

First Normal Form

• Each table cell should contain a single value.
• Each record needs to be unique

Second Normal Form:

"Single Column Primary Key"

A relation must be in first normal form and relation must not contain any partial dependency.

"No non-prime attribute"

example:

Third Normal Form:

Has no transitive functional dependencies

example:

Boyce-Codd Normal Form

Boyce-Codd Normal Form (BCNF) is an extension of Third Normal Form on strict terms

For any non-trivial functional dependency, X → A, X must be a super-key.

Denormalization :

Denormalization is a strategy used on a previously-normalized database to increase performance. In computing, denormalization is the process of trying to improve the read performance of a database, at the expense of losing some write performance, by adding redundant copies of data or by grouping data.