Normalization
Normalization is the process breaking down large unorganized database table to organizing data table in a database. This includes creating tables and establishing relationships between those tables according to rules designed both to protect the data and to make the database more flexible by eliminating redundancy and inconsistent dependency.
The first goal during data normalization is to detect and remove all duplicate data by logically grouping data redundancies together. Whenever a piece of data is dependent on another, the two should be stored in proximity within that data set.
As with many formal rules and specifications, normalization requires additional tables and find. There are six normal forms including Boyce-Codd Normal Form (BCNF). Note: “NF” refers to “normal form”. They are: –
Types of Normalization:-
- First normal form (1NF)
- Second normal form (2NF)
- Third normal form (3NF)
- Boyce-Codd Normal Form (BCNF)
- Fourth Normal Form (4NF)
- Fifth Normal Form (5NF)
- Sixth Normal Form (6NF) Proposed
| Normal Form | Description |
| 1NF | A relation is in 1NF if it contains an atomic value. |
| 2NF | A relation will be in 2NF if it is in 1NF and all non-key attributes are fully functional dependent on the primary key. |
| 3NF | A relation will be in 3NF if it is in 2NF and no transition dependency exists. |
| BCNF | A stronger definition of 3NF is known as Boyce Codd’s normal form. |
| 4NF | A relation will be in 4NF if it is in Boyce Codd’s normal form and has no multi-valued dependency. |
| 5NF | A relation is in 5NF. If it is in 4NF and does not contain any join dependency, joining should be lossless. |