normaliseringstekniker

Normaliseringstekniker, or normalization techniques, are methods used in database design to organize data in a way that reduces redundancy and improves data integrity. The process involves dividing a database into two or more tables and defining relationships between the tables. This technique is based on the principles of normalization, which were introduced by Edgar F. Codd in 1970.

The first normal form (1NF) requires that each table cell contains only a single value, and each record needs to be unique. The second normal form (2NF) builds on 1NF by ensuring that all non-key attributes are fully functionally dependent on the primary key. The third normal form (3NF) further refines 2NF by eliminating transitive dependencies, where non-key attributes are dependent on other non-key attributes.

Beyond 3NF, there are additional normal forms such as Boyce-Codd Normal Form (BCNF), Fourth Normal Form (4NF), and Fifth Normal Form (5NF), each addressing more specific types of anomalies and dependencies. These higher normal forms are less commonly used in practice due to their complexity and the potential for over-normalization, which can lead to performance issues.

Normalization is crucial for maintaining data consistency and reducing redundancy, but it must be balanced with the need for efficient data retrieval. In practice, databases often achieve a level of normalization that is sufficient for their specific requirements, rather than adhering strictly to the highest normal forms.