Database Normalisation Questions Medium
The normalization process involves several steps to ensure that a database is organized efficiently and eliminates data redundancy. The steps involved in the normalization process are as follows:
1. First Normal Form (1NF): In this step, the database is structured in a way that each column contains only atomic values, meaning that it cannot be further divided. Additionally, each row in the table should be uniquely identifiable.
2. Second Normal Form (2NF): In this step, the database is further refined by ensuring that all non-key attributes are fully dependent on the primary key. This means that any attribute that is partially dependent on the primary key is moved to a separate table.
3. Third Normal Form (3NF): In this step, the database is normalized to eliminate transitive dependencies. Transitive dependencies occur when an attribute depends on another attribute that is not part of the primary key. To achieve 3NF, these dependencies are removed by creating separate tables.
4. Fourth Normal Form (4NF): This step focuses on eliminating multi-valued dependencies. Multi-valued dependencies occur when a non-key attribute depends on a combination of attributes that are part of the primary key. To achieve 4NF, these dependencies are removed by creating separate tables.
5. Fifth Normal Form (5NF): Also known as Project-Join Normal Form (PJNF), this step eliminates join dependencies. Join dependencies occur when a table can be decomposed into smaller tables without losing any information. To achieve 5NF, these dependencies are removed by creating separate tables.
It is important to note that not all databases need to be normalized up to the fifth normal form. The level of normalization depends on the specific requirements and complexity of the database.