Database Management

Database Management

The relational model is based on organizing the data in tabular form. Data manipulation is done according to the mathematical concept of relation of set theory, that is to say, the relational algebra. The relational algebra was invented in 1970 by EF Codd, director of IBM Research Center in San Jose. It consists of a set of formal operations on relations. Relational operations can create a new relation (table) from elementary operations on other tables (e.g. union, intersection, or difference).Set theory involves two concepts; the notion of domain and the notion of Cartesian product.

Concept of Field

A domain is a finite or infinite set ...