Normalization is the process of organizing data in a database to reduce data redundancy and dependency, and to ensure data consistency and accuracy. The goal of normalization is to eliminate data duplication and update anomalies, which can lead to inconsistencies in the database.
There are several levels of normalization, each with its own set of rules and guidelines:
First Normal Form (1NF): In this level of normalization, data is organized into tables, with each table consisting of a primary key and one or more attributes. Each attribute contains only atomic values, meaning it cannot be further subdivided.
Second Normal Form (2NF): In this level of normalization, all non-key attributes are dependent on the entire primary key, not just a part of it. This means that no attribute is dependent on a non-key attribute.
Third Normal Form (3NF): In this level of normalization, all non-key attributes are dependent on the primary key, and not on other non-key attributes.
Boyce-Codd Normal Form (BCNF): In this level of normalization, all attributes in a table are functionally dependent on the primary key. This means that for any given value of the primary key, there can be only one corresponding value for each attribute in the table.
Fourth Normal Form (4NF): In this level of normalization, multi-valued dependencies are eliminated from the database.
Fifth Normal Form (5NF): In this level of normalization, join dependencies are eliminated from the database.
Normalization is an iterative process and each level builds on the previous one. Normalizing a database can help to improve its efficiency, reduce storage space, and make it easier to maintain and update.
