Normálformát

Normálformát, often translated as "normal form," is a concept used in relational database design. Its primary purpose is to reduce data redundancy and improve data integrity. Data is organized into tables, and normal form refers to a set of rules or guidelines that dictate how the attributes (columns) and tuples (rows) of a relation (table) are structured.

The process of normalization involves dividing larger tables into smaller, less redundant tables and defining relationships between them. This helps to avoid anomalies that can occur during data insertion, deletion, or modification. There are several normal forms, each building upon the previous one with more stringent requirements.

The most commonly discussed normal forms are First Normal Form (1NF), Second Normal Form (2NF), and Third Normal Form (3NF). 1NF requires that all attributes be atomic and that there are no repeating groups of columns. 2NF builds on 1NF by requiring that all non-key attributes be fully functionally dependent on the primary key. 3NF further refines this by eliminating transitive dependencies, meaning that non-key attributes should not be dependent on other non-key attributes. Higher normal forms, such as Boyce-Codd Normal Form (BCNF) and Fourth Normal Form (4NF), exist to address more complex dependency issues, but 3NF is often considered sufficient for most practical applications. Normalization is a crucial step in creating efficient and maintainable database schemas.