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

The USPTO Linked Patent Dataset release ( 2017-02-24T17:18:51+01:00 by Mofeed Hassan)

2017-02-24T17:18:51+01:00 by Mofeed Hassan

Dear all, We are happy to announce USPTO Linked Patent Dataset release. Patents are widely used to protect intellectual property and a measure of innovation output. Read more about "The USPTO Linked Patent Dataset release"

Two accepted papers in ESWC 2017 ( 2017-02-22T17:43:38+01:00 by Dr. Mohamed Ahmed Sherif)

2017-02-22T17:43:38+01:00 by Dr. Mohamed Ahmed Sherif

Hello Community! We are very pleased to announce the acceptance of two papers in ESWC 2017 research track. The ESWC 2017 is to be held in Portoroz, Slovenia from 28th of May to the 1st of June. Read more about "Two accepted papers in ESWC 2017"

AKSW Colloquium, 13th February, 3pm, Evaluating Entity Linking ( 2017-02-09T15:53:07+01:00 Michael Roeder)

2017-02-09T15:53:07+01:00 Michael Roeder

On the 13th of February at 3 PM, Michael Röder will present the two papers “Evaluating Entity Linking: An Analysis of Current Benchmark Datasets and a Roadmap for Doing a Better Job” of van Erp et al. Read more about "AKSW Colloquium, 13th February, 3pm, Evaluating Entity Linking"

SLIPO project kick-off meeting ( 2017-02-03T12:59:48+01:00 by Sandra Bartsch)

2017-02-03T12:59:48+01:00 by Sandra Bartsch

SLIPO, a new InfAI project kicked-off between the 18th and 20th of January in Athens, Greece. Funded by the EU-program “Horizon 2020”, the project is planned to have an operational time until the 31st of December 2019. Read more about "SLIPO project kick-off meeting"

AKSW Colloquium 30.Jan.2017 ( 2017-01-30T13:24:04+01:00 by Simon Bin)

2017-01-30T13:24:04+01:00 by Simon Bin

In the upcoming Colloquium, Simon Bin will discuss the paper “Towards Analytics Aware Ontology Based Access to Static and Streaming Data” by Evgeny Kharlamov et.al. that has been presented at ISWC2017. Read more about "AKSW Colloquium 30.Jan.2017"