A primer on relational data base concepts

Relational data base systems present the user with simple, high-level data base processing. These systems incorporate features that complement network and hierarchical systems. The following are the five main complementary features of the relational approach: • Table data structures are easy to understand. • Tables provide increased data independence as compared to present implementations of hierarchies and networks. • Table operations are powerful and still easy to use. • Table operations have a sound theoretical foundation. • Table operations may be generalized to data definition.