Intelligent Information Systems (I2S)
Research project: Ontop

Ontology-based Data Access through Virtual Knowledge Graphs

Ontop is a Virtual Knowledge Graph System initiated by the eponymous research group at the Free University of Bozen-Bolzano and continued today by Bozen-Bolzano researchers in collaboration with a vibrant international community, with Guohui Xiao as an active core team member.

Ontop VKG
Ontop, UiB

Main content

Ontop is a Virtual Knowledge Graph system, which exposes the content of arbitrary relational databases as knowledge graphs. These graphs are virtual, which means that data remains in the data sources instead of being moved to another database.

Ontop translates SPARQL queries expressed over the knowledge graphs into SQL queries executed by the relational data sources. It relies on R2RML mappings and can take advantage of lightweight ontologies.