06-09-2017, 11:28 AM
Database normalization or simply normalization is the process of organizing the columns (attributes) and tables (relationships) of a relational database to reduce data redundancy and improve data integrity. Normalisation is also the process of simplifying the design of a database to achieve the optimal structure. It was first proposed by Edgar F. Codd, as an integral part of a relational model.
Normalisation involves arranging attributes in relation based on dependencies between attributes, ensuring that dependencies are properly enforced by database integrity constraints. Normalisation is achieved by applying some formal rules either by a process of synthesis or decomposition. Synthesis creates a standardized database design based on a known set of dependencies. Decomposition takes an existing database design (insufficiently normalized) and improves it based on the known set of dependencies.
Edgar F. Codd, inventor of the relational model (RM), introduced the concept of normalization and what is now known as the first normal form (1NF) in 1970. Codd went on to define the second normal form (2NF) and third (1971) ). Codd and Raymond F. Boyce defined the normal Boyce-Codd (BCNF) form in 1974. Informally, a relational database relationship is often described as "normalized" if it complies with the third normal form. Most 3NF relationships are free from insertion, update, and deletion anomalies.
Normalisation involves arranging attributes in relation based on dependencies between attributes, ensuring that dependencies are properly enforced by database integrity constraints. Normalisation is achieved by applying some formal rules either by a process of synthesis or decomposition. Synthesis creates a standardized database design based on a known set of dependencies. Decomposition takes an existing database design (insufficiently normalized) and improves it based on the known set of dependencies.
Edgar F. Codd, inventor of the relational model (RM), introduced the concept of normalization and what is now known as the first normal form (1NF) in 1970. Codd went on to define the second normal form (2NF) and third (1971) ). Codd and Raymond F. Boyce defined the normal Boyce-Codd (BCNF) form in 1974. Informally, a relational database relationship is often described as "normalized" if it complies with the third normal form. Most 3NF relationships are free from insertion, update, and deletion anomalies.