Home history Edgar F. Codd Edgar F. Codd
The inventor made relational databases possible
Edgar Codd, with his chin resting on his hand, in which he's holding a pencil

Edgar F. “Ted” Codd was a mathematician and computer scientist best known for his trailblazing work on the relational model that led to the multibillion-dollar database industry. The revolutionary power of relational databases is taken for granted today, but in 1970 the concept was merely theoretical.

That’s when Codd, an Oxford-educated mathematician working at the IBM San Jose Research Laboratory (now IBM Research – Almaden) in San Jose, California, published a paper describing a system that could store and access information without providing a formal organizational structure or even recording exact locations for data. Until that time, retrieving information typically involved employing specialists to write programs to extract precise data lots. Relational databases shifted this dynamic, making it easy for laypeople to easily access data.

Databases have since become the standard means for accessing everything from bank and credit card accounts to travel reservations, online purchases and stocks.

A seminal publication
Envisioning a new way to access information

Born in 1923 on the Isle of Portland in Dorset, on the south coast of England, Codd earned mathematics and chemistry degrees from Exeter College at Oxford University. He flew in the Royal Air Force during World War II, moved to New York in 1948, and a year later joined IBM as a mathematical programmer, working on the company’s first electromechanical computer, the Selective Sequence Electronic Calculator. In the early 1950s, he became involved in the design and development of the IBM 701, the company’s first commercially available computer for scientific processing.

Dismayed by US Senator Joseph McCarthy’s Communist-baiting amid the Cold War, Codd left the US in 1953 for Ottawa, where he worked for Computing Devices of Canada. He returned to the US in 1957 after a chance meeting with his previous IBM manager. Working out of the company’s offices in Poughkeepsie, New York, he helped design the IBM 7030 (known as STRETCH), which was the first transistorized supercomputer and progenitor of IBM’s 7090 mainframe technology. He also led the team that developed the world’s first multiprogramming system, enabling independently created programs to execute simultaneously while sharing a central processing unit.

In 1961, Codd attended the University of Michigan on an IBM scholarship. He obtained a master’s degree and doctorate in computer science in Ann Arbor, along with his US citizenship. He joined IBM’s San Jose lab in 1968 and two years later published his seminal paper, “A Relational Model of Data for Large Shared Data Banks.”

In the publication, Codd imagined a software architecture through which users could access information without knowing the database’s physical blueprint. He introduced a concept for a database that organized information into tables that could be linked — or related — based on common characteristics. This enabled users to retrieve a new table with a single query and enabled businesses to quickly and easily gain insights from data in order to make decisions and identify opportunities.

A transformational technology
Stress testing Codd’s creation

Codd’s novel system was recognized immediately as potentially transformational, but it had to be tested. A group of programmers in 1973 spearheaded an industrial-strength implementation known as the System R project. The team included Don Chamberlin, who with Raymond Boyce co-created Structured Query Language (SQL), and Patricia Selinger, who developed a cost-based optimizer that made relational databases more efficient. Raymond Lorie, who invented a compiler that could save database query plans for later use, also contributed.

Chamberlin and Boyce developed SQL and systems for automatically translating high-level queries into efficient plans for execution. Their efforts led to a host of IBM products, including the IBM DB2 database management system. (Larry Ellison’s company Relational Software, later renamed Oracle, produced the first commercially available relational database in 1977.) DB2 was first shipped in 1983 on the MVS mainframe platform. It became widely recognized as the premier database management product for mainframes and spread to the worlds of parallel processors and desktop operating systems.

Today, it is used on everything from handheld devices to supercomputers and remains a foundational component for countless data transactions, including at ATMs and for online purchases.

Awards and remembrances
He ushered in a new realm of innovation

Codd was highly decorated for his many achievements. He was named a fellow of the British Computer Society in 1974 and an IBM Fellow in 1976. He received what is widely considered the field’s highest honor, the Turing Award from the Association of Computing Machinery, in 1981. In 1994, he was elected a member of the American Academy of Arts and Sciences. In 2002, Forbes magazine listed Codd’s relational model as one of the most important innovations of the previous 85 years. He died in 2003 at age 79.

Chris Date, a relational data expert who worked on DB2 at IBM before becoming Codd’s business partner, described his colleague’s essential achievement in the New York Times obituary: “… before Dr. Codd’s work found its way into commercial products, electronic databases were ‘completely ad hoc and higgledy-piggledy.’”

At the time of his death, Janet Perna, who was then responsible for IBM’s relational database products, summarized Codd’s accomplishments: “His remarkable vision and intellectual genius ushered in a whole new realm of innovation that has shaped the world of technology today, but perhaps his greatest achievement is inspiring generations of people who continue to build on the foundations he laid.”

Date added, “Codd’s biggest overall achievement was to make database management into a science.”


In 2002, Forbes listed Codd’s relational model as one of the most important innovations of the previous 85 years
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