We have compared the performance of five non-commercial triple stores, Virtuoso-open source, Jena SDB, Jena TDB, SWIFT-OWLIM and 4Store. We examined three performance aspects: the ...
Vladimir Mironov, Nirmala Seethappan, Ward Blond&e...
The join operation, which combines tuples from multiple relations, is the most fundamental and, typically, the most expensive operation in database queries. The standard approach t...
Benjamin J. McMahan, Guoqiang Pan, Patrick Porter,...
Personalization is a powerful mechanism that helps users to cope with the abundance of information on the Web. Database query personalization achieves this by dynamically construc...
Research on query optimization has focused almost exclusively on reducing query execution time, while important qualities such as consistency and predictability have largely been ...
Complex queries often contain common or similar subexpressions, either within a single query or among multiple queries submitted as a batch. If so, query execution time can be imp...
Jingren Zhou, Johann Christoph Freytag, Per-Å...
We have developed a system to process database queries over composed data providing web services. The queries are transformed into execution plans containing an operator that invok...