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

AKSW Colloquium, 18-05-2015, Multilingual Morpheme Ontology, Personalised Access and Enrichment of Linked Data Resources ( 2015-05-17T12:24:52+02:00 by Dr. Amrapali Zaveri)

2015-05-17T12:24:52+02:00 by Dr. Amrapali Zaveri

MMoOn – A Multilingual Morpheme Ontology by Bettina Klimek In the last years a rapid emergence of lexical resources evolved in the Semantic Web. Read more about "AKSW Colloquium, 18-05-2015, Multilingual Morpheme Ontology, Personalised Access and Enrichment of Linked Data Resources"

AKSW Colloquium, 11-05-2015, DBpedia distributed extraction framework ( 2015-05-10T18:36:42+02:00 by Nilesh Chakraborty)

2015-05-10T18:36:42+02:00 by Nilesh Chakraborty

Scaling up the DBpedia extraction framework by Nilesh Chakraborty The DBpedia extraction framework extracts different kinds of structured information from Wikipedia to generate various datasets. Performing a full extraction of Wikipedia dumps of all languages (or even just the mapping-based languages) takes a significant amount of time. Read more about "AKSW Colloquium, 11-05-2015, DBpedia distributed extraction framework"

Invited talk @AIMS webinar series ( 2015-05-08T12:47:00+02:00 by Dr. Amrapali Zaveri)

2015-05-08T12:47:00+02:00 by Dr. Amrapali Zaveri

On 5th of May Ivan Ermilov on behalf of AKSW presented CKAN data catalog as a part of AIMS (Agricultural Information Management Standards) webinar series. Read more about "Invited talk @AIMS webinar series"

AKSW Colloquium, 04-05-2015, Automating RDF Dataset Transformation and Enrichment, Structured Machine Learning in Life Science ( 2015-05-03T21:50:38+02:00 by Mohamed Sherif)

2015-05-03T21:50:38+02:00 by Mohamed Sherif

Automating RDF Dataset Transformation and Enrichment by Mohamed Sherif With the adoption of RDF across several domains, come growing requirements pertaining to the completeness and quality of RDF datasets. Read more about "AKSW Colloquium, 04-05-2015, Automating RDF Dataset Transformation and Enrichment, Structured Machine Learning in Life Science"

AKSW Colloquium, 27-04-2015, Ontotext’s RDF database-as-a-service (DBaaS) via Self-Service Semantic Suite (S4) platform via & Knowledge-Based Trust ( 2015-04-23T17:21:00+02:00 JoergUnbehauen)

2015-04-23T17:21:00+02:00 JoergUnbehauen

This colloquium features two talks. First the Self-Service Semantic Suite (S4) platform is presented by Marin Dimitrov (Ontotext), followed up by Jörg Unbehauens report on Googles effort on using factual correctness as a ranking factor. Read more about "AKSW Colloquium, 27-04-2015, Ontotext’s RDF database-as-a-service (DBaaS) via Self-Service Semantic Suite (S4) platform via & Knowledge-Based Trust"