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

Publications

by (Editors: ) [BibTex of ]

News

Hajira Jabeen and Ricardo Usbeck at AKSW Colloquium, Monday, 3rd August 2015, 3pm ( 2015-08-03T13:13:16+02:00 by Ricardo Usbeck)

2015-08-03T13:13:16+02:00 by Ricardo Usbeck

Hybrid Question Answering at QALD 5 challenge by Ricardo Usbeck The plethora of datasets on the web, both structured and unstructured, enables answering complex questions such as “Which anti-apartheid activist was born in Mvezo? Read more about "Hajira Jabeen and Ricardo Usbeck at AKSW Colloquium, Monday, 3rd August 2015, 3pm"

DL-Learner 1.1 (Supervised Structured Machine Learning Framework) Released ( 2015-07-22T16:14:57+02:00 by Dr. Jens Lehmann)

2015-07-22T16:14:57+02:00 by Dr. Jens Lehmann

Dear all, we are happy to announce DL-Learner 1.1. DL-Learner is a framework containing algorithms for supervised machine learning in RDF and OWL. Read more about "DL-Learner 1.1 (Supervised Structured Machine Learning Framework) Released"

AKSW Colloquium, 20-07-2015, Enterprise Linked Data Networks ( 2015-07-16T11:20:08+02:00 by Marvin Frommhold)

2015-07-16T11:20:08+02:00 by Marvin Frommhold

Enterprise Linked Data Networks (PhD progress report) by Marvin Frommhold The topic of the thesis is the scientific utilization of the LUCID research project, in particular the LUCID Endpoint Prototype. Read more about "AKSW Colloquium, 20-07-2015, Enterprise Linked Data Networks"

AKSW Colloquium, 13-07-2015 ( 2015-07-13T12:06:56+02:00 by Philipp Frischmuth)

2015-07-13T12:06:56+02:00 by Philipp Frischmuth

Philipp Frischmuth will give a brief presentation regarding the current state of his PhD thesis and Lukas Eipert will present the topic of his upcoming internship: As part of an internship at eccenca a configurable graphical RDF editor will be … Continue reading → Read more about "AKSW Colloquium, 13-07-2015"

AKSW Colloquium, 22-06-2015, Concept Expansion Using Web Tables, Mining entities from the Web, Linked Data Stack ( 2015-06-22T12:11:56+02:00 by Mohamed Sherif)

2015-06-22T12:11:56+02:00 by Mohamed Sherif

Concept Expansion Using Web Tables by Chi Wang, Kaushik Chakrabarti, Yeye He,Kris Ganjam, Zhimin Chen, Philip A. Bernstein (WWW’2015), presented by Ivan Ermilov: Abstract. Read more about "AKSW Colloquium, 22-06-2015, Concept Expansion Using Web Tables, Mining entities from the Web, Linked Data Stack"