3 citations · 9 across the 11 of their papers we have counts for
7 papers · 1 filter
Certain Answers to a SPARQL Query over a Knowledge Base (extended version)
Julien Corman, Guohui Xiao
Ontology-Mediated Query Answering (OMQA) is a well-established framework to answer queries over an RDFS or OWL Knowledge Base (KB). OMQA was originally designed for unions of conju…
Enriching Ontology-based Data Access with Provenance (Extended Version)
Diego Calvanese, Davide Lanti, Ana Ozaki +2
Ontology-based data access (OBDA) is a popular paradigm for querying heterogeneous data sources by connecting them through mappings to an ontology. In OBDA, it is often difficult t…
Efficient Handling of SPARQL OPTIONAL for OBDA (Extended Version)
Guohui Xiao, Roman Kontchakov, Benjamin Cogrel +2
OPTIONAL is a key feature in SPARQL for dealing with missing information. While this operator is used extensively, it is also known for its complexity, which can make efficient eva…
Cost-Driven Ontology-Based Data Access (Extended Version)
Davide Lanti, Guohui Xiao, Diego Calvanese
In ontology-based data access (OBDA), users are provided with a conceptual view of a (relational) data source that abstracts away details about data storage. This conceptual view i…
Data Scaling in OBDA Benchmarks: The VIG Approach
Davide Lanti, Guohui Xiao, Diego Calvanese
In this paper we describe VIG, a data scaler for benchmarks in the context of ontology-based data access (OBDA). Data scaling is a relatively recent approach, proposed in the datab…
OBDA Constraints for Effective Query Answering (Extended Version)
Dag Hovland, Davide Lanti, Martin Rezk +1
In Ontology Based Data Access (OBDA) users pose SPARQL queries over an ontology that lies on top of relational datasources. These queries are translated on-the-fly into SQL queries…
Expressivity and Complexity of MongoDB (Extended Version)
Elena Botoeva, Diego Calvanese, Benjamin Cogrel +1
A significant number of novel database architectures and data models have been proposed during the last decade. While some of these new systems have gained in popularity, they lack…