Relational database theory took shape in the 1960s and 1970s, and most of the thinking and enthusiasm behind it came from Dr. Edgar Frank “Ted” Codd, while working at IBM’s Almaden Research Labs in a then nascent Silicon Valley.
Dr. Codd, born August 19, 1923 on the Isle of Portland in England, studied mathematics and chemistry at Exeter College, Oxford, before serving as a pilot in the Royal Air Force during World War II. He moved to New York in 1948 to work for IBM as a mathematical programmer, but five years later migrated to Ottawa, Canada as a response to the rhetoric of Senator Joseph McCarthy. Not long after he returned to the United States, and in 1965 received a PhD in computer science from the University of Michigan, Ann Arbor. Two years later he again began working for IBM, this time at their research laboratory in San Jose, California, where he soon revolutionized database software by advocating a new relational model for database management.
Based on set theory (a branch of mathematical logic), Dr. Codd’s relational database model was developed at a time when most database platforms employed a hierarchical system, commonly known as the Codasyl database approach, in which the structure of data had to be defined within each application program. Dr. Codd’s relational database used a new query language (eventually becoming SEQUEL and later SQL) to access any combination of data stored in cross-referenced tables.
After an internal IBM paper a year earlier, Dr. Codd outlined his concept in A Relational Model of Data for Large Shared Data Banks published in 1970. However, due to vested interests in IBM’s then current hierarchical database approaches, such as IMS/DB, Dr. Codd’s ideas were not adopted until commercial rivals began implementing them. Eventually in 1981 IBM released its first commercial relational database management system in the form of SQL/DS (Structured Query Language/Data System), and in 1983 released DB2, also SQL based, for the MVS operating system. The two products have coexisted since then, but SQL/DS was rebranded as DB2 for VM and VSE in the late 1990s.
The relational database model has since made its way into countless successful products, including Microsoft SQL Server, Microsoft Access, Microsoft FoxPro and Visual FoxPro, dataBased Intelligence dBase, Alaska Software XBase++, Apollo Database Engine, Apycom Software DBFView, Astersoft DBF Manager, Digital Equipment Rdb (now Oracle Rdb), DS-Datasoft Visual DBU, Elsoft DBF Commander, GrafX Software Clipper and Vulcan.NET, Informix (now IBM Infomix), Multisoft FlagShip, Oracle Database, Recital Software Recital, Relational Technology Ingres, Software Perspectives Cule.Net, Sybase, and xHarbour.com xHarbour, to name a few, and the list goes on.
Dr. Codd did not become wealthy from his ideas, but he received many accolades, and will long be remembered. In 2004 SIGMOD (Association for Computing Machinery), which specializes in large-scale data management problems and databases, renamed its highest prize to the SIGMOD Edgar F. Codd Innovations Award, in his honor.
The inventor of the relational database system died on April 18, 2003 of heart failure at his home in Williams Island, Florida, at the age of 79.