Relational database

A relational database is a digital database based on the relational model of data, as proposed by E. F. Codd in 1970.A software system used to maintain relational databases is a relational database management system (RDBMS). Virtually all relational database systems use SQL (Structured Query Language) for querying and maintaining the database. A relational database is a digital database based on the relational model of data, as proposed by E. F. Codd in 1970.A software system used to maintain relational databases is a relational database management system (RDBMS). Virtually all relational database systems use SQL (Structured Query Language) for querying and maintaining the database. The term 'relational database' was invented by E. F. Codd at IBM in 1970. Codd introduced the term in his research paper 'A Relational Model of Data for Large Shared Data Banks'.In this paper and later papers, he defined what he meant by 'relational'. One well-known definition of what constitutes a relational database system is composed of Codd's 12 rules. However, no commercial implementations of the relational model conform to all of Codd's rules, so the term has gradually come to describe a broader class of database systems, which at a minimum: In 1974, IBM began developing System R, a research project to develop a prototype RDBMS.However, the first commercially available RDBMS was Oracle, released in 1979 by Relational Software, now Oracle Corporation.Other examples of an RDBMS include DB2, SAP Sybase ASE, and Informix. In 1984, the first RDBMS for Macintosh began being developed, code-named Silver Surfer, it was later released in 1987 as 4th Dimension and known today as 4D.