Component development and construction for database design

Principles for database modeling were developed and intensively investigated in the late 1970s and early 1980s. They are based on concepts such as supertypes and subtypes, restructuring through normalization, type construction by constructors, generic models, and associations with pre-specified semantic meaning, e.g., classified relationship types. Use of these principles can result in large and complex database schemas that are difficult for developers to understand, integrate, and extend. We observe that often such schemas consist of identifiable sub-schemas that are loosely coupled. We use this observation to develop a design theory aimed at component-based construction of schemata. Building blocks used for schema construction are termed kernel components. Kernel components are composed to form more complex components by the application of the component constructors. Our approach allows a developer to derive an understandable schema topography for very large and complex databases.