Sparqlify: a SPARQL-SQL rewriter

Sparqlify is a SPARQL-SQL rewriter that enables one to define RDF views on relational databases and query them with SPARQL. It is currently in alpha state and powers the Linked-Data Interface of the LinkedGeoData Server – i.e. it provides access to billions of virtual triples from the OpenStreetMap database.

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Key Features

  • A novel syntax for view definitions inspired by SQL's CREATE VIEW statement. We believe this to lower the learning curve for defining RDB-RDF mappings.
  • A query is rewritten into a single SQL statement, giving all control over query planning to the underlying database system.
  • Support of geo-spatial functions: In general, Sparqlify supports mapping custom SPARQL functions to relational ones. Some mappings for PostGIS are already provided (e.g. intersection with polygons).

Limitations

Please be aware that Sparqlify is currently in alpha state and the following limitations hold:

  • For the moment, only the PostgreSQL database system is supported.
  • Only a subset of SPARQL 1.0 + Sub-Queries is supported: For instance, the implementation of aggregate functions including COUNT is still pending.
  • Support for Sparql 1.1 property paths is very unlikely in the near future.

Publications

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News

AKSW Colloquium, 04.07.2016. Big Data, Code Quality. ( 2016-06-29T12:34:35+02:00 by Ivan Ermilov)

2016-06-29T12:34:35+02:00 by Ivan Ermilov

On the upcoming Monday (04.07.2016), AKSW group will discuss topics related to Semantic Web and Big Data as well as programming languages and code quality. Read more about "AKSW Colloquium, 04.07.2016. Big Data, Code Quality."

Accepted Papers of AKSW Members @ Semantics 2016 ( 2016-06-27T12:50:01+02:00 Sandra Bartsch)

2016-06-27T12:50:01+02:00 Sandra Bartsch

This year’s SEMANTiCS conference which is taking place between September 12 – 15, 2016 in Leipzig recently invited for the submission of research papers on semantic technologies. Read more about "Accepted Papers of AKSW Members @ Semantics 2016"

AKSW Colloquium, 27.06.2016, When owl:sameAs isn’t the Same + Towards Versioning for Arbitrary RDF Data ( 2016-06-26T15:46:24+02:00 by Marvin Frommhold)

2016-06-26T15:46:24+02:00 by Marvin Frommhold

In the next Colloquium, June the 27th at 3 PM, two papers will be presented: When owl:sameAs isn’t the Same: An Analysis of Identity in Linked Data André Valdestilhas will present the paper “When owl:sameAs isn’t the Same: An Analysis of Identity … Continue reading → Read more about "AKSW Colloquium, 27.06.2016, When owl:sameAs isn’t the Same + Towards Versioning for Arbitrary RDF Data"

Should I publish my dataset under an open license? ( 2016-06-22T11:41:28+02:00 by Dr.-Ing. Sebastian Hellmann)

2016-06-22T11:41:28+02:00 by Dr.-Ing. Sebastian Hellmann

Undecided, stand back we know flowcharts:   Taken from my slides for my keynote  at TKE: Linguistic Linked Open Data, Challenges, Approaches, Future Work from Sebastian Hellmann Read more about "Should I publish my dataset under an open license?"

TKE 2016 has announced their invited speakers ( 2016-06-14T12:58:29+02:00 Sandra Bartsch)

2016-06-14T12:58:29+02:00 Sandra Bartsch

The 12th International Conference on Terminology and Knowledge Engineering (TKE 2016) has announced their invited speakers, including Dr. Read more about "TKE 2016 has announced their invited speakers"