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.

Current Team

Publications

by (Editors: ) [BibTex of ]

News

Two AKSW Papers at ESWC 2015 ( 2015-03-24T13:38:00+01:00 by Mohamed Sherif)

2015-03-24T13:38:00+01:00 by Mohamed Sherif

We are very pleased to announce that two of our papers were accepted for presentation as full research papers at ESWC 2015. Read more about "Two AKSW Papers at ESWC 2015"

AKSW Colloquium, 03-23-2015, Git Triple Store and From CPU bringup to IBM Watson ( 2015-03-23T10:58:38+01:00 by Ricardo Usbeck)

2015-03-23T10:58:38+01:00 by Ricardo Usbeck

From CPU bring up to IBM Watson by Kay Müller, visiting researcher, IBM Ireland Working in a corporate environment like IBM offers many different opportunities to work on the bleeding edge of research and development. Read more about "AKSW Colloquium, 03-23-2015, Git Triple Store and From CPU bringup to IBM Watson"

ALIGNED project kick-off ( 2015-03-03T12:43:29+01:00 MartinBruemmer)

2015-03-03T12:43:29+01:00 MartinBruemmer

ALIGNED, AKSW’s new H2020-funded project, kicked off in Dublin. Read more about "ALIGNED project kick-off"

AKSW Colloquium: Tommaso Soru and Martin Brümmer on Monday, March 2 at 3.00 p.m. ( 2015-02-27T13:57:27+01:00 by Amrapali Zaveri)

2015-02-27T13:57:27+01:00 by Amrapali Zaveri

On Monday, 2nd of March 2015, Tommaso Soru will present ROCKER, a refinement operator approach for key discovery. Martin Brümmer will then present NIF annotation and provenance – A comparison of approaches. Read more about "AKSW Colloquium: Tommaso Soru and Martin Brümmer on Monday, March 2 at 3.00 p.m."

AKSW Colloquium: Edgard Marx and Tommaso Soru on Monday, February 23, 3.00 p.m. ( 2015-02-19T22:53:47+01:00 TommasoSoru)

2015-02-19T22:53:47+01:00 TommasoSoru

On Monday, 23rd of February 2015, Edgard Marx will introduce Smart, a search engine designed over the Semantic Search paradigm; subsequently, Tommaso Soru will present ROCKER, a refinement operator approach for key discovery. Read more about "AKSW Colloquium: Edgard Marx and Tommaso Soru on Monday, February 23, 3.00 p.m."