CONCEPTUAL DESIGN PATTERNS FOR RELATIONAL DATABASES

Database design patterns (DDPs) at the semantic level are introduced. A definition of conceptual DDPs is provided and the issues of their representation, their independence from the implementation details and from the logical data model, as well as some behavioural aspects, are discussed. We argue in favor of conceptual DDPs as a mechanism of abstraction and synthesis, and as a way improve the quality of a database design. Moreover, DDPs can be supported by rigorous mathematical theories (e.g., functional dependencies and normalisation). Two examples of DDPs (Multiple Roles, Hierarchy) are analysed in depth, which will also show how the Extended Entity-Relationship model can be enhanced to capture more integrity constraints.