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 aggregate queries over ontologies. In this work we investigate the latter problem. We propose syntax and semantics for epistemic aggregate queries over ontologies and study query answering for MAX, MIN, COUNT, CNTD, SUM, AVG queries for the ontology language DL-LiteA.
In REF the syntax and semantics for epistemic aggregate queries over ontologies were proposed, and query answering for typical aggregate functions studied for an ontology language DL-Lite A .
Aggregate queries over ontologies
ONISW '08
Computer Science