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.

Publications

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News

AKSW Colloquium, 25.04.2016, DISPONTE, Workbench for Big Data Dev ( 2016-04-22T16:05:08+02:00 by Mohamed Sherif)

2016-04-22T16:05:08+02:00 by Mohamed Sherif

In this colloquium, Frank Nietzsche will present his master thesis titled “Game Theory- distributed solving” Game theory analyzes the behavior of individuals in complex situations. One popular game in Europe and North America with such a complex situation is Skat. Read more about "AKSW Colloquium, 25.04.2016, DISPONTE, Workbench for Big Data Dev"

AKSW Colloquium, 18.04.2016, DISPONTE, Workbench for Big Data Dev ( 2016-04-18T10:17:10+02:00 by Patrick Westphal)

2016-04-18T10:17:10+02:00 by Patrick Westphal

In this week’s Colloquium, today 18th of April at 3 PM, Patrick Westphal will present the paper ‘Probabilistic Description Logics under the Distribution Semantics‘ by Riguzzi et. al. Abstract Representing uncertain information is crucial for modeling real world domains. Read more about "AKSW Colloquium, 18.04.2016, DISPONTE, Workbench for Big Data Dev"

AKSW Colloquium, 11.04.2016, METEOR with DBnary ( 2016-04-11T09:07:18+02:00 by Ricardo Usbeck)

2016-04-11T09:07:18+02:00 by Ricardo Usbeck

In this week’s Colloquium, today 11th of April at 3 PM, Diego Moussallem will present the paper by Zied Elloumi et al. titled “METEOR for Multiple Target Languages using DBnary.” [PDF]. Read more about "AKSW Colloquium, 11.04.2016, METEOR with DBnary"

AKSW Colloquium, 04.04.2016, AMIE + Structured Feedback ( 2016-04-04T13:51:45+02:00 by Lorenz Bühmann)

2016-04-04T13:51:45+02:00 by Lorenz Bühmann

In this week’s Colloquium, today 4th of April at 3 PM, Lorenz Bühmann will present the paper by Galárraga et al. titled “AMIE: Association Rule Mining under Incomplete Evidence in Ontological Knowledge Bases.” [PDF]. Read more about "AKSW Colloquium, 04.04.2016, AMIE + Structured Feedback"

International Semantic Web Community meets in Leipzig, Sept. 12-15, 2016 ( 2016-03-29T11:40:27+02:00 Sandra Bartsch)

2016-03-29T11:40:27+02:00 Sandra Bartsch

At the annual SEMANTiCS Conference, experts from academia and industry meet to discuss semantic computing, its benefits and future business implications. Read more about "International Semantic Web Community meets in Leipzig, Sept. 12-15, 2016"