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 “Towards an Open Question Answering Architecture” conference pre-presentation on Monday, August 18 in P702 ( 2014-08-15T13:14:53+02:00 by Konrad Höffner)

2014-08-15T13:14:53+02:00 by Konrad Höffner

Towards an Open Question Answering Architecture On Monday, August 18 ,13.30, Edgard Marx, will give a pre-presentation of his Semantics’ conference talk about the accepted paper Towards an Open Question Answering Architecture. About the AKSW Colloquium This event is part of a series of events about Semantic Web technology. Please see http://wiki.aksw. Read more about "AKSW Colloquium “Towards an Open Question Answering Architecture” conference pre-presentation on Monday, August 18 in P702"

AKSW member will participate in ECAI 2014, Prague, Czech Republic ( 2014-08-15T10:09:23+02:00 RicardoUsbeck)

2014-08-15T10:09:23+02:00 RicardoUsbeck

Hello! The  21st European Conference  on Artificial Intelligence (ECAI) will be held in the city of Prague, Czech  Republic from 18th to 22nd August 2014. Various excellent papers on artificial intellegence, logic, rule mining and many more topics will be presented. Read more about "AKSW member will participate in ECAI 2014, Prague, Czech Republic"

Additional contributions to SEMANTiCS 2014 ( 2014-08-05T10:31:12+02:00 RicardoUsbeck)

2014-08-05T10:31:12+02:00 RicardoUsbeck

Hello again! Unfortunately, we missed the opportunity to inform you about other contributions of AKSW to the SEMANTiCS 2014. First, we missed to tell you about another accepted paper: Towards Question Answering on Statistical Linked Data ( Konrad Höffner and Jens Lehmann) Second, there is also another excellent and interesting series of workshops. Read more about "Additional contributions to SEMANTiCS 2014"

Five AKSW Papers at SEMANTiCS 2014 ( 2014-08-01T16:54:00+02:00 RicardoUsbeck)

2014-08-01T16:54:00+02:00 RicardoUsbeck

Hello Community! We are very pleased to announce that five of our papers were accepted for presentation at SEMANTiCS 2014.  The papers cover architectures for Big Data Search Engines, Linked Data Visualisations, Machine Learning and Dataset Descriptions. Read more about "Five AKSW Papers at SEMANTiCS 2014"

AKSW Colloquium “Knowledge Extraction and Presentation” on Monday, July 28, 3.00 p.m. in Room P702 ( 2014-07-24T11:55:13+02:00 by Konrad Höffner)

2014-07-24T11:55:13+02:00 by Konrad Höffner

Knowledge Extraction and Presentation On Monday, July 28,  in room P702 at 3.00 p.m., Edgard Marx proposes a question answering system. He has a computer science background (BSc. and MSc. in Computer Science/PUC-Rio) and is a member of AKSW (Agile Knowledge Engineering and Semantic Web). Read more about "AKSW Colloquium “Knowledge Extraction and Presentation” on Monday, July 28, 3.00 p.m. in Room P702"