Description logics (DLs) have a long tradition in computer science and knowledge
representation, being designed so that domain knowledge can be described and so that …

The chase algorithm is a fundamental tool for query evaluation and for testing query
containment under tuple-generating dependencies (TGDs) and equality-generating …

In this paper we study data complexity of answering conjunctive queries over description
logic (DL) knowledge bases constituted by a TBox and an ABox. In particular, we are …

Answering conjunctive queries (CQs) over a set of facts extended with existential rules is a
prominent problem in knowledge representation and databases. This problem can be …

A robust system for ontology-based data access should provide meaningful answers to
queries even when the data conflicts with the ontology. This can be accomplished by …

The basic idea of the combined approach to query answering in the presence of ontologies
is to materialize the consequences of the ontology in the data and then use a limited form of …

Datalog∃ is the extension of Datalog, allowing existentially quantified variables in rule
heads. This language is highly expressive and enables easy and powerful knowledge …

This chapter is a survey of the history and the main concepts of Datalog. We begin with an
introduction to the language and its use for database definition and querying. We then look …

The need for reasoning over temporal data has recently emerged. DatalogMTL is a highly
suitable language to handle many real-world applications. In spite of the deep theoretical …

Answering conjunctive queries over ontology-enriched datasets is a core reasoning task for
many applications. Query answering is, however, computationally very expensive, which …