Chris Date and the Relational Model
Chris Date is famous for his writings on relational theory. At IBM in the seventies, and afterwards, he was a friend and colleague of Edgar Codd, who invented the principles of the relational database. Chris took on the role of communicating and teaching Codd's relational theory, and reluctantly admits to a role in establishing SQL as the dominant relational language. Richard Morris interviews the well-known author and computer scientist
Source: red-gate.com