IBM System R

System R is an IBM San Jose Research Center (now IBM Almaden Research Center) developed database management system. The system was developed in the 70s as part of a research project. It is of great historical importance because it was the first relational database management system and the query language SEQUEL ( Structured English Query Language = ) defined, from which emerged the SQL query language. On the basis of this research Edgar F. Codd was heavily involved.

System R was already apparent by a good transaction performance and had an advanced query optimizer, and B- trees as an index method. The R system has been true for some customers of IBM successfully tested, but never commercialized.

Due to the experience with the system R has been developed and used since 1981 for customers of the IBM system SQL / DS. SQL / DS is the predecessor of the relational database management system DB2.

The works of Edgar F. Codd inspired other software developers outside of IBM. Larry Ellison founded Software Development Laboratories in 1977, the company and developed the relational database management system Oracle. Later the name of the database has been adopted as the company name (company).

The SQL query language has prevailed until today as a standard. It was first adopted by ANSI in 1986 and 1987 as a standard by ISO. In subsequent years, the SQL standard has been expanded significantly.