O'Reilly logo

UML and Data Modeling: A Reconciliation by David Hay

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

As an alternative to the hard-coded hierarchical approach, in 1970, Dr. Edward Codd presented his relational theory to the world.[65] Based on set theory in mathematics, it provided a systematic way to organize data so that they reflected their meaning. This further had the effect of reducing redundancy. While there were no hidden links between elements, the only redundancy required was to explicitly describe such links. It took a few years for the industry to recognize the implications of his discovery, but by the end of the decade, commercial relational databases were on the market.

Dr. Codds insight was that data could most effectively be managed in terms of two-dimensional relations. The term relation was derived ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required