Quality-driven Integration of Heterogeneous Information Systems

Integrated access to information that is spread over multiple, distributed, and heterogeneous sources is an important problem in many scientific and commercial domains. While much work has been done on query processing and choosing plans under cost criteria, very little is known about the important problem of incorporating the information quality aspect into query planning. In this paper we describe a framework for multidatabase query processing that fully includes the quality of information in many facets, such as completeness, timeliness, accuracy, etc. We seamlessly include information quality into a multidatabase query processor based on a view-rewriting mechanism. We model information quality at different levels to ultimately find a set of high-quality query-answering plans