Users often do not require a complete answer to their query but rather only a sample. They expect the sample to be either the largest possible or the most representative (or both)...
An important means of allowing non-expert end-users to pose ad hoc queries — whether over single databases or data integration systems — is through keyword search. Given a set...
Similarity search has been proved suitable for searching in very large collections of unstructured data objects. We are interested in efficient parallel query processing under si...
Most operations of the relational algebra or SQL require a sorted stream of tuples for efficient processing. Therefore, processing complex relational queries relies on efficient a...
Data Stream Management Systems (DSMSs) must support optimized execution scheduling of multiple continuous queries on massive, and frequently bursty, data streams. Previous approac...