A formal view integration method

Abstract

The design of an appropriate conceptual database scheme is one of the most difficult tasks in usual database applications. Especially, the design of a common global database scheme for many different user groups requires a great amount of effort and skill, because the desired scheme should fit a great variety of requirements and expectations. Here, view integration is a natural method that should help to manage the complexity of such a design problem. For each user group the requirements and expectations are separately collected and specified as views, that are subsequently integrated into a global scheme supporting all those different views. In this paper, we carefully develop a formal model, clarifying many notions and concepts, related to the view integration method. This formal model serves as a theoretical basis of our integration approach that uses equivalence preserving, local scheme transformations as the main integration operations.