With the increasing number of XML repositories on the World Wide Web, it is essential to provide support for XML views so that users can view the data from different perspective. Existing systems for XML views only support selection operation applied in the views and do not guarantee that the designed views are valid. In this paper, we propose a systematic approach to design valid XML views. There are three main steps in our approach. First, we transform the semistructured XML source documents into a semantically rich Object-Relationship-Attribute model designed for SemiStructured data (ORA-SS). Second, we enrich the ORA-SS diagram with semantics such as participation constraints of object classes and distinguishing between attributes of object classes and relationship types, which cannot be expressed in the XML document. These additional semantics will allow us to validate XML views subsequently. Third, we use the additional semantics to develop a set of rules to guide the design of valid XML views. We identify four transformation operations for creating XML views, namely, selection, projection, join and swap operations, and develop a comprehensive algorithm that checks for the validity of XML views constructed by applying the 4 operations.
REF propose a technique to design XML views, which are guaranteed to be valid.
Designing Valid XML Views
Proceedings of the 21st International Conference on Conceptual Modeling (ER '02
Computer Science