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QLever

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QLever
Original author(s)Hannah Bast, Björn Buchhold, et al.[1]
Initial release2017; 7 years ago (2017)
Repositorygithub.com/ad-freiburg/qlever
Written inC++
Standard(s)SPARQL
Available inEnglish
TypeGraph database
LicenseApache License
Websiteqlever.cs.uni-freiburg.de

QLever (pronounced /ˈklɛvər/ KLEH-ver, as in "clever") is an 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.[1] A specialized user interface for QLever predictively autocompletes SPARQL queries.[2]

QLever is one of the candidates to replace Blazegraph as the triplestore for the Wikidata Query Service. A 2023 study found that, compared to other triplestores, QLever achieved fast execution of successful queries but offered limited support for complex SPARQL constructs.[3]

Contents

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The official QLever server provides access to the following datasets:[4]

Although the QLever engine lacks support for GeoSPARQL functions per se, the official server precomputes a subset of GeoSPARQL relationships into dedicated triples for OpenStreetMap and OpenHistoricalMap data.[5]

See also

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References

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  1. ^ a b Bast & Buchhold 2017.
  2. ^ Bast et al. 2021.
  3. ^ Lam, An Ngoc; Elvesæter, Brian; Martin-Recuerda, Francisco (2023). Evaluation of a Representative Selection of SPARQL Query Engines Using Wikidata. Extended Semantic Web Conference. Lecture Notes in Computer Science. Vol. 13870. Springer, Cham – via SpringerLink.
  4. ^ "QLever". Freiburg im Breisgau: University of Freiburg Chair for Algorithms and Data Structures. Retrieved 13 July 2024.
  5. ^ Bast et al. 2021.

Further reading

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