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Database normalization is the process of structuring a relational database accordance with a series of so-called normal forms in order to reduce data redundancy and improve data integrity. It was first proposed by British computer scientist Edgar F. Codd as part of his relational model .
The sixth normal form is currently as of 2009 being used in some data warehouses where the benefits outweigh the drawbacks, [9] for example using anchor modeling.Although using 6NF leads to an explosion of tables, modern databases can prune the tables from select queries (using a process called 'table elimination' - so that a query can be solved without even reading some of the tables that the ...
The purpose of this normalization is to increase flexibility and data independence, and to simplify the data language. It also opens the door to further normalization, which eliminates redundancy and anomalies. Most relational database management systems do not support nested records, so tables are in first normal form by default.
Boyce–Codd normal form (BCNF or 3.5NF) is a normal form used in database normalization. It is a slightly stricter version of the third normal form (3NF). By using BCNF, a database will remove all redundancies based on functional dependencies .
Domain-key normal form (DK/NF or DKNF) is a normal form used in database normalization which requires that the database contains no constraints other than domain constraints and key constraints. A domain constraint specifies the permissible values for a given attribute, while a key constraint specifies the attributes that uniquely identify a ...
Other forms of data, typically associated with signal processing (including audio and imaging) or machine learning, can be normalized in order to provide a limited range of values. In content management , the concept of a single source of truth (SSOT) is applicable, just as it is in database normalization generally and in software development .
Normal forms are database normalization levels which determine the "goodness" of a table. Generally, the third normal form is considered to be a "good" standard for a relational database. [citation needed] Normalization aims to free the database from update, insertion and deletion anomalies.
SEQUEL was designed to manipulate and retrieve data in relational databases. By 1974, Chamberlin and Boyce published “SEQUEL: A Structured English Query Language” which detailed their refinements to SQUARE and introduced us to the data retrieval aspects of SEQUEL. [5] It was one of the first languages to use Edgar F. Codd's relational model.