Abstract. The last decade has seen an increase in the number of available corpus query systems. These systems generally implement a query language as well as a database model. We r...
The class of unions of conjunctive queries (UCQ) has been shown to be particularly well-behaved for data exchange; its certain answers can be computed in polynomial time (in terms...
Answering queries over ontologies is an important issue for the Semantic Web. Aggregate queries were widely studied for relational databases but almost no results are known for ag...
Diego Calvanese, Evgeny Kharlamov, Werner Nutt, Ca...
There is much effort to develop comprehensive support for the storage and querying of XML data in database management systems. The major developers have extended their systems to h...
Parke Godfrey, Jarek Gryz, Andrzej Hoppe, Wenbin M...
Abstract. Controlled languages (CLs) are ambiguity-free subsets of natural languages such as English offering a good trade-off between the formal rigor of ontology and query langua...