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

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"

AKSW Colloquium, 15-06-2015, Caching for Link Discovery ( 2015-06-12T23:33:25+02:00 TommasoSoru)

2015-06-12T23:33:25+02:00 TommasoSoru

Using Caching for Local Link Discovery on Large Data Sets [PDF] by Mofeed Hassan Engineering the Data Web in the Big Data era demands the development of time- and space-efficient solutions for covering the lifecycle of Linked Data. Read more about "AKSW Colloquium, 15-06-2015, Caching for Link Discovery"

AKSW Colloquium, 08-06-2015, DBpediaSameAs, Dynamic-LOD ( 2015-06-05T02:00:35+02:00 by Dr. Amrapali Zaveri)

2015-06-05T02:00:35+02:00 by Dr. Amrapali Zaveri

DBpediaSameAs: An approach to tackling heterogeneity in DBpedia identifiers by Andre Valdestilhas This work provides an approach to tackle heterogeneity about a problem where several transient owl:sameAs redundant occurrences were found in DBpedia identifiers during searching for owl:sameAs occurrences that … Continue reading → Read more about "AKSW Colloquium, 08-06-2015, DBpediaSameAs, Dynamic-LOD"

Smart Data Web project kick-off ( 2015-06-01T13:55:29+02:00 MartinBruemmer)

2015-06-01T13:55:29+02:00 MartinBruemmer

Smart Data Web, a new BMWi funded project kicked-off in Berlin. Central goal of Smart Data Web is leveraging state-of-the-art data extraction and enrichment technologies as well as Linked Data to create value-added systems for German industry. Read more about "Smart Data Web project kick-off"

AKSW Colloquium, 01-06-2015, MEX – Publishing ML Experiment Results, Scaling DL-Learner – Status and Plans ( 2015-05-31T22:23:34+02:00 by Simon Bin)

2015-05-31T22:23:34+02:00 by Simon Bin

MEX – Publishing ML Experiment Results by Diego Esteves Over the decades many machine learning experiments have been published, collaborating with the scientific community progress. Read more about "AKSW Colloquium, 01-06-2015, MEX – Publishing ML Experiment Results, Scaling DL-Learner – Status and Plans"