Query answering in Ontology Based Data Access (OBDA) exploits the knowledge of an ontology’s TBox to deal with incompleteness of the ABox (or data source). Current query-answerin...
A common approach to performing keyword search over relational databases is to find the minimum Steiner trees in database graphs. These methods, however, are rather expensive as th...
Given a dataset P and a preference function f, a top-k query retrieves the k tuples in P with the highest scores according to f. Even though the problem is well-studied in convent...
— Location-based services (LBS) have been widely accepted by mobile users. Many LBS users have direction-aware search requirement that answers must be in a search direction. Howe...
Over the last decades, improvements in CPU speed have outpaced improvements in main memory and disk access rates by orders of magnitude, enabling the use of data compression techn...