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QLever
QLever (pronounced , as in "clever") is an Open-source software, open-source triplestore and graph database developed by a team at the University of Freiburg led by Hannah Bast. QLever performs high-performance queries of semantic Web knowledge bases, including full-text search within text corpuses. A specialized user interface for QLever predictively autocompletes SPARQL queries. Characteristics A 2023 study compared QLever with Virtuoso Universal Server, Virtuoso, Blazegraph, GraphDB, Stardog, Apache Jena, and Oxigraph. The study investigated a QLever version from 2021, concluding that it achieved fast execution of successful queries but offered limited support for complex SPARQL constructs. Contents The official QLever instance provides API endpoints for querying the following datasets: * Wikidata * Wikimedia Commons * Freebase (database), Freebase * OpenStreetMap * OpenHistoricalMap * UniProt * PubChem * DBLP * OpenCitations * IMDb * Integrated Authority File * YAGO (dat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GeoSPARQL
GeoSPARQL is a model for representing and querying geospatial linked data for the Semantic Web. It is standardized by the Open Geospatial Consortium as OGC GeoSPARQL. The definition of a small ontology based on well-understood OGC standards is intended to provide a standardized exchange basis for geospatial RDF data which can support both qualitative and quantitative spatial reasoning and querying with the SPARQL database query language. The Ordnance Survey Linked Data Platform uses OWL mappings for GeoSPARQL equivalent properties in its vocabulary. ThLinkedGeoDatadata set is a work of the Agile Knowledge Engineering and Semantic Web (AKSW) research group at the University of Leipzig, a group mostly known for DBpedia, that uses the GeoSPARQL vocabulary to represent OpenStreetMap data. In particular, GeoSPARQL provides for: * a small topological ontology in RDFS/ OWL for representation using ** Geography Markup Language (GML) and well-known text representation of geometry (WKT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
