Normalization in Database Design

Normalization in database design is the process of organizing data in a database to reduce redundancy and dependency by dividing large tables into smaller tables and defining relationships between them. It helps in improving data integrity and reducing anomalies in the database.

Forms of Normalization

1. First Normal Form (1NF): In 1NF, all columns in a table are atomic and cannot be further divided. Each column contains only a single value, and there are no repeating groups.
2. Second Normal Form (2NF): In 2NF, a table is in 1NF, and all non-key attributes are fully dependent on the primary key. There should be no partial dependency of any column on the primary key.
3. Third Normal Form (3NF): In 3NF, a table is in 2NF, and no transitive dependencies exist. A transitive dependency occurs when a non-key attribute depends on another non-key attribute, which is dependent on the primary key.
4. Boyce-Codd Normal Form (BCNF): BCNF is a stricter form of 3NF where every determinant is a candidate key. It eliminates all anomalies and ensures data integrity.
5. Fourth Normal Form (4NF): In 4NF, multi-valued dependencies are dealt with, and a table is further decomposed to remove any such dependencies.
6. Fifth Normal Form (5NF) or Project-Join Normal Form (PJ/NF): 5NF deals with cases where a table contains join dependencies that arise from multitable relationships.