Relational database management system: Difference between revisions

Revision as of 02:34, 7 September 2003

Revision as of 05:14, 9 January 2004

Line 1:

A '''relational database management system''' is a [[database management system]] that is based on the [[relational model]] as introduced by [[Edgar F. Codd]]. Strictly speaking it should also satisfy [[Codd's 12 rules]] but in practice there is no DBMS that satisfies all these rules. In fact, most succesfulsuccessful DBMSs (and the query language [[SQL]]) that are considered to be relational violate the relational model in several important ways. However, most database practitioners and researchers use the term in a loose way such that most databases that support SQL are also included.

The first released RDBMS that was a relatively faithful implementation of the relational model was the [[Multics Relational Data Store]], first sold in [[1978]]. Others have been [[Berkeley Ingres QUEL]] and [[IBM BS12]].