Local as view information integration in the Semantic Model approach

The problem of large-scale, decentralized data sharing, which is relevant for a wide range of applications, is still a source of major theoretical and practical challenges in spite of many years of sustained research. The Semantic-Model approach to information integration was introduced recently. In this approach, the mediator schema is a simple ontological view of the sources´ data, consisting of a collection of binary relations. This paper extends query processing and optimization in the Semantic Model approach with local-as-view (LAV) mappings. It has been argued that local-as-view is the approach of choice for information integration applications, providing significant flexibility and better query optimization opportunities. We will concentrate on XML information sources, provide relational-to-XML mappings to describe source contents in terms of the mediator schema, and present query processing and optimization algorithms for this framework.