Query Decomposition, Optimization and Processing in Multidatabase Systems

Query Scrambling in Distributed Multidatabase Systems

This work addresses the problem of efficient query processing in multidatabase systems distributed over widearea networks. The solution unifies the query scrambling and reduction approaches to dynamic optimization of query processing plans at the data integration stage. The paper presents a new data integration algorithm based on query scrambling and the extended reduction technique. The algori...

Dynamic Query Optimization and Query Processing in Multidatabase Systems

Approximate Processing for Medical Record Linking and Multidatabase Analysis

In this article we investigate how approximate query processing (AQP) can be used in medical multidatabase systems. We identify two areas where this estimation technique will be of use. First, approximate query processing can be used to preprocess medical record linking in the multidatabase. Second, approximate answers can be given for aggregate queries. In the case of multidatabase systems use...

Quality-driven Integration of Heterogenous Information Systems

Integrated access to information that is spread over multiple, distributed, and heterogeneous sources is an important problem in many scienti c 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 desc...

An Extended SQL for Fuzzy Multidatabases

ABSTRACT Many real world problems involve imprecise and ambiguous information rather than crisp information. Recent trends in the database paradigm are to incorporate fuzzy sets to tackle imprecise and ambiguous information of real world problems. Fuzzy query processing in multidatabases have been extensively studied, however, the same has rarely been addressed for fuzzy multidatabases. In this...