The availability of streaming data sources is progressively increasing thanks to the
development of ubiquitous data capturing technologies such as sensor networks. The …

While big data analytics is considered as one of the most important paths to competitive
advantage of today's enterprises, data scientists spend a comparatively large amount of time …

Recent years have seen an increasing interest in ontology-mediated query answering, in
which the semantic knowledge provided by an ontology is exploited when querying data …

Ontological queries are evaluated against an enterprise ontology rather than directly on a
database. The evaluation and optimization of such queries is an intriguing new problem for …

Databases and related information systems can benefit from the use of ontologies to enrich
the data with general background knowledge. The DL-Lite family of ontology languages was …

RDF Database Systems is a cutting-edge guide that distills everything you need to know to
effectively use or design an RDF database. This book starts with the basics of linked open …

This paper presents Graal, a java toolkit dedicated to ontological query answering in the
framework of existential rules. We consider knowledge bases composed of data and an …

Recently several inconsistency-tolerant semantics have been introduced for querying
inconsistent description logic knowledge bases. Most of these semantics rely on the notion …

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 …

The OWL 2 QL profile has been designed to facilitate query answering via query rewriting.
This paper presents an optimized query rewriting algorithm which takes advantage of the …