Normalization is a database design technique that is used to minimize redundancy and dependency in a database. It involves organizing the columns (attributes) and tables (relations) of a database in a specific way to minimize duplication and ensure that data is stored in a logical and organized manner.
The goal of normalization is to create a database structure that is efficient, flexible, and easy to maintain. There are several normal forms that are used to guide the process of normalization, including first normal form (1NF), second normal form (2NF), third normal form (3NF), and Boyce-Codd normal form (BCNF).
Here’s a brief overview of each normal form:
- First normal form (1NF): This is the most basic form of normalization, and it requires that each column in a table contains a single value and that each row is unique. This means that each column must be atomic (i.e., not made up of multiple values), and each row must contain a unique set of values.
- Second normal form (2NF): In addition to meeting the requirements of 1NF, a table must also be in 2NF if it is free of any partial dependencies. A partial dependency occurs when a non-key attribute depends on only a part of a composite primary key.
- Third normal form (3NF): In addition to meeting the requirements of 1NF and 2NF, a table must also be in 3NF if it is free of any transitive dependencies. A transitive dependency occurs when a non-key attribute depends on another non-key attribute.
- Boyce-Codd normal form (BCNF): This is the most stringent form of normalization, and it requires that a table be in 3NF and that all determinants (i.e., attributes that determine the value of another attribute) are part of the primary key.
By following the normalization process, you can ensure that your database is well-structured, easy to maintain, and free of redundancy and dependency. This can lead to improved performance, accuracy, and flexibility, as well as a reduced risk of data loss or corruption.