|
|
Relational Database
A type of database in which all data is represented in two-dimensional tables with rows for "entities" (customers, orders, warehouses, etc.) and columns for "attributes" (ID number, name, delivery date, etc.). In addition, there is a set of rules that defines how information should be stored in these tables and how relationships between different items should be represented. Relational databases were invented by E.F. Codd who, in 1970, published a paper showing how concepts from mathematical set theory could be used to organize computer databases. Along with precise specifications for how data should be stored, Codd designed a concise set of data manipulation operations that are easily understood and implemented, yet cover all actions that software might need to perform on data. It is this rigorous mathematical approach that distinguishes relational databases from earlier ways of representing data. By using a small number of precise rules to describe how data should be stored and manipulated, relational databases are able to be simple yet highly flexible. Not all products calling themselves "relational databases" really follow all of Codd's rules. But most database systems in use today are, to a greater or lesser degree, relational. |
home | corporate overview | consulting services | articles | demos | success stories | products | glossary | search | contact
© 2000 Chalem Systems Group
|