The relational database concept was described first by Dr. Edgar F. Codd in an IBM research publication entitled “System R4 Relational” appearing in 1970. Initially, it was unclear whether any system based on this concept could achieve commercial success. Nevertheless, Relational Software, Incorporated (RSI) began in 1977 and released Oracle as the world’s first relational database within a couple of years. By 1985, Oracle could claim more than 1,000 relational database customer sites. By comparison, IBM would not embrace relational technology in a commercial product until the Query Management Facility in 1983
