In the 1960s and 1970s, he worked out his theories of data arrangement, issuing his paper "A Relational Model of Data for Large Shared Data Banks"[18] in 1970, after an internal IBM paper one year earlier.[19] To his disappointment, IBM proved slow to exploit his suggestions until commercial rivals started implementing them.[20]
Initially, IBM refused to implement the relational model to preserve revenue from IMS/DB, a hierarchical database the company promoted in the 1970s.[21] Codd then showed IBM customers the potential of the implementation of its model, and they, in turn, pressured IBM. Then IBM included in its Future Systems project a System R subproject – but put in charge of it developers who were not thoroughly familiar with Codd's ideas, and isolated the team from Codd.[22][23] As a result, they did not use Codd's own Alpha language but created a non-relational one, SEQUEL. Even so, SEQUEL was so superior to pre-relational systems that in 1979 it was copied by Larry Ellison, based on pre-launch papers presented at conferences of Relational Software Inc, in his Oracle Database, which actually reached the market before SQL/DS – because of the then-already proprietary status of the original name, SEQUEL had to be renamed to SQL.
As the relational model became fashionable in the early 1980s, Codd fought a sometimes bitter campaign to prevent the term from being misused by database vendors who had merely added a relational veneer to older technology. As part of this campaign, he published his 12 rules to define what constituted a relational database. This made his position at IBM increasingly difficult, so he left to form a consulting company with Chris Date and others.
Codd coined the term Online analytical processing (OLAP) and wrote the "twelve laws of online analytical processing".[26] Controversy erupted, however, after it was discovered that this paper had been sponsored by Arbor Software (subsequently Hyperion, now acquired by Oracle), a conflict of interest that had not been disclosed, and Computerworld withdrew the paper.[27]
^"Edgar F. ("Ted") Codd". A. M. Turing award. he volunteered for active duty and became a flight lieutenant in the Royal Air Force Coastal Command, flying Sunderlands
^ abO’Regan, Gerard (2013). Giants of Computing: A Compendium of Select, Pivotal Pioneers. Dordrecht: Springer Science & Business Media. p. 75. ISBN978-1-4471-5339-9.
^Rubenstein, Steve. "Edgar F. Codd – computer pioneer in databases." San Francisco Chronicle 24 April 2003: A21. Gale Biography in Context. Web. 1 December 2011.
^ abCampbell-Kelly, Martin (1 May 2003). "Edgar Codd". The Independent. Archived from the original on 9 December 2010. Retrieved 24 October 2011.
^Codd, Edgar (1965). Propagation, Computation, and Construction in Two-dimensional cellular spaces (PhD thesis). University of Michigan. ProQuest302172044.
^Codd, Edgar Frank (1968). Cellular Automata. London: Academic Pr. ISBN978-0-12-178850-6.