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

Jekyll RDF Tutorial Screencast ( 2018-08-07T11:11:12+02:00 by Natanael Arndt)

2018-08-07T11:11:12+02:00 by Natanael Arndt

Since 2016 we are developing Jekyll-RDF a plugin for the famous Jekyll–static website generator. Read more about "Jekyll RDF Tutorial Screencast"

DBpedia Day @ SEMANTiCS 2018 ( 2018-07-20T14:37:25+02:00 by Johannes Frey)

2018-07-20T14:37:25+02:00 by Johannes Frey

Don’t miss the 12th edition of the DBpedia Community Meeting in Vienna, the city with the highest quality of life in the world. Read more about "DBpedia Day @ SEMANTiCS 2018"

SANSA 0.4 (Semantic Analytics Stack) Released ( 2018-06-26T18:33:38+02:00 by Prof. Dr. Jens Lehmann)

2018-06-26T18:33:38+02:00 by Prof. Dr. Jens Lehmann

We are happy to announce SANSA 0.4 – the fourth release of the Scalable Semantic Analytics Stack. Read more about "SANSA 0.4 (Semantic Analytics Stack) Released"

AKSW is organizing the 6th Leipzig Semantic Web Day (LSWT2018) ( 2018-04-17T14:14:17+02:00 by Natanael Arndt)

2018-04-17T14:14:17+02:00 by Natanael Arndt

On June 18th 2018 we will have the 6th Leipzig Semantic Web Day (LSWT2018). A platform for regional actors to get in touch with each other regarding Semantic Web topics. Read more about "AKSW is organizing the 6th Leipzig Semantic Web Day (LSWT2018)"

SANSA 0.3 (Semantic Analytics Stack) Released ( 2017-12-18T11:15:38+01:00 by Simon Bin)

2017-12-18T11:15:38+01:00 by Simon Bin

Dear all, We are happy to announce SANSA 0.3 – the third release of the Scalable Semantic Analytics Stack. Read more about "SANSA 0.3 (Semantic Analytics Stack) Released"