Relational Database Management System

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What Does Relational Database Management System Mean?

A relational database management system (RDBMS) is a database engine/system based on the relational model specified by Edgar F. Codd–the father of modern relational database design–in 1970.

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Most modern commercial and open-source database applications are relational in nature. The most important relational database features include an ability to use tables for data storage while maintaining and enforcing certain data relationships.

Techopedia Explains Relational Database Management System

In 1970, Edgar F. Codd, a British computer scientist with IBM, published “A Relational Model of Data for Large Shared Data Banks.” At the time, the renowned paper attracted little interest, and few understood how Codd’s groundbreaking work would define the basic rules for relational data storage, which can be simplified as:

  1. Data must be stored and presented as relations, i.e., tables that have relationships with each other, e.g., primary/foreign keys.
  2. To manipulate the data stored in tables, a system should provide relational operators – code that enables the relationship to be tested between two entities. A good example is the WHERE clause of a SELECT statement, i.e., the SQL statement SELECT * FROM CUSTOMER_MASTER WHERE CUSTOMER_SURNAME = ’Smith’ will query the CUSTOMER_MASTER table and return all customers with a surname of Smith.

Codd later published another paper that outlined the 12 rules that all databases must follow to qualify as relational. Many modern database systems do not follow all 12 rules, but these systems are considered relational because they conform to at least two of the 12 rules.

Most modern commercial and open-source database systems are relational in nature and include well-known applications, e.g., Oracle DB (Oracle Corporation); SQL Server (Microsoft) and MySQL and Postgres (open source).

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Margaret Rouse
Senior Editor
Margaret Rouse
Senior Editor

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.