Normalization

Definition: A process of organizing the data in the most efficient way

Benefits:

1. Eliminate data redundancy
2. Improve performance
3. Query optimization
4. Faster update due to less number of columns in one table
5. Index improvement

1^st NF:

1. Removes      repetitive groups
2. Create a PK

2^nd NF:

1. Should be in 1^st NF
2. Remove   columns which create duplicate data in a table and creates a new table with Primary Key – Foreign Key relationship

3^rd NF:

1. Should be in 2^nd NF
2. Remove those non-key attributes (which are not PK) which can be derived from other non-key attributes.

Country can be derived from State also… so removing country

BCNF NF:

1. Should be in 3^rd NF
2. If PK is composed of multiple columns then all non-key attribute should be derived from FULL PK only. If some non-key attribute can be derived from partial PK then remove it