Extending View Technology for Complex Integration Tasks1

Abstract In this paper, we present extensions to the MultiView object-oriented database view system that improve its ability to integrate electronic computer-aided design (ECAD) tools. Using an object-preserving algebra as the view definition language, the MultiView system supports data transformations to suit the needs of individual tools. However, an object-preserving algebra alone is not powerful enough to express recursive transformations such as transitive path derivations and the flattening of hierarchical structures. In order to provide these capabilities, we extend the view definition language with operators that permit complex transformations of the data. To achieve performance essential for ECAD tools, we introduce the mediator class as a general strategy for the materialization of these complex views. We compare the bounds on query and update performance of our set-based mediator class for the symmetric transitive closure with a more traditional object-based materialization strategy.