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.

Project Team

Former Members

Publications

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News

LDK conference @ University of Leipzig ( 2019-03-22T09:21:41+01:00 by Julia Holze)

2019-03-22T09:21:41+01:00 by Julia Holze

With the advent of digital technologies, an ever-increasing amount of language data is now available across various application areas and industry sectors, thus making language data more and more valuable. Read more about "LDK conference @ University of Leipzig"

13th DBpedia community meeting in Leipzig ( 2019-02-22T12:22:07+01:00 by Julia Holze)

2019-02-22T12:22:07+01:00 by Julia Holze

We are happy to invite you to join the 13th edition of the DBpedia Community Meeting, which will be held in Leipzig. Read more about "13th DBpedia community meeting in Leipzig"

SANSA 0.5 (Semantic Analytics Stack) Released ( 2018-12-13T09:25:34+01:00 by Prof. Dr. Jens Lehmann)

2018-12-13T09:25:34+01:00 by Prof. Dr. Jens Lehmann

We are happy to announce SANSA 0.5 – the fifth release of the Scalable Semantic Analytics Stack. Read more about "SANSA 0.5 (Semantic Analytics Stack) Released"

AKSW at web.br in São Paulo ( 2018-10-22T09:37:49+02:00 by Natanael Arndt)

2018-10-22T09:37:49+02:00 by Natanael Arndt

From October 1st until 6th a delegation from AKSW Group, Leipzig University of Applied Sciences (HTWK), eccenca GmbH, and Max Planck Institute for Human Cognitive and Brain Sciences went to São Paulo, Brazil to meet people from the Web Technologies … Continue reading → Read more about "AKSW at web.br in São Paulo"

AskNow 0.1 Released ( 2018-09-13T15:35:04+02:00 by Prof. Dr. Jens Lehmann)

2018-09-13T15:35:04+02:00 by Prof. Dr. Jens Lehmann

Dear all, we are very happy to announce AskNow 0.1 – the initial release of Question Answering Components and Tools over RDF Knowledge Graphs. Website: http://asknow.sda.tech/ Demo: http://asknowdemo.sda.tech GitHub: https://github. Read more about "AskNow 0.1 Released"