Database Normalisation Questions Medium
The third normal form (3NF) is a level of database normalization that ensures data integrity and eliminates data redundancy in a relational database. It builds upon the first and second normal forms (1NF and 2NF) by further reducing data duplication and dependency.
To achieve 3NF, a table must meet the following criteria:
1. It should already be in 2NF.
2. All non-key attributes (columns) must be functionally dependent on the primary key.
3. There should be no transitive dependencies, meaning that non-key attributes should not depend on other non-key attributes.
The importance of 3NF lies in its ability to improve database performance, reduce storage requirements, and enhance data consistency. By eliminating data redundancy and dependency, 3NF minimizes the chances of data inconsistencies and anomalies, such as update anomalies, insertion anomalies, and deletion anomalies.
Furthermore, 3NF simplifies database maintenance and modification. Since data is stored in a more organized and normalized manner, it becomes easier to update, insert, and delete records without affecting other parts of the database. This flexibility and ease of maintenance are crucial for ensuring data accuracy and reliability in a database system.
In summary, the third normal form (3NF) is important because it enhances data integrity, reduces redundancy, eliminates data anomalies, improves database performance, and simplifies database maintenance and modification.