Query Optimization over Web Databases
by Mourad Ouzzani
 

Querying multiple information sources (especially databases) has been largely studied in the two last decades, e.g., distributed databases, multidatabases, information retrieval systems, etc. Nevertheless, the peculiarities of the new context, i.e., the Internet and the Web, require new approaches to deal with the different issues. Indeed, support for scalability (information providers and information consumers), high distribution, autonomy and heterogeneity, new users' requirements, etc. should be provided while tackling any querying related issue. The viability and usefulness of the query infrastructure depends essentially on the development of an efficient and effective query optimization strategy. Our work will be mainly dedicated to issues on query optimization. We are trying to propose a new query optimization paradigm based on the notion of quality of service. Users will formulate QoS constraints over the execution of their queries and the query engine will have to resolve these queries while fulfilling the constraints.