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

Former Members

Publications

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News

DBpedia Knowledge Engineering PhD Symposium ( 2022-05-02T16:59:37+02:00 by Julia Holze)

2022-05-02T16:59:37+02:00 by Julia Holze

Dear all,  We are excited to invite you to the 1st DBpedia Knowledge Engineering PhD Symposium, organized on July 6th, 2022 in Leipzig, Germany. Read more about "DBpedia Knowledge Engineering PhD Symposium"

Tutorial @ Knowledge Graph Conference 2022 ( 2022-04-25T12:24:06+02:00 by Julia Holze)

2022-04-25T12:24:06+02:00 by Julia Holze

On May 2, 2022 we will organize a tutorial 2.0 at the Knowledge Graph Conference (KGC) 2022. Read more about "Tutorial @ Knowledge Graph Conference 2022"

International Workshop on Data-driven Resilience Research 2022 ( 2022-04-21T14:43:27+02:00 by Julia Holze)

2022-04-21T14:43:27+02:00 by Julia Holze

In the face of continuously changing contextual conditions and ubiquitous disruptive crisis events, the concept of resilience refers to some of the most urgent, challenging, and interesting issues of nowadays society. Read more about "International Workshop on Data-driven Resilience Research 2022"

DBpedia @ Google Summer of Code Program 2022 ( 2022-03-23T14:26:48+01:00 by Julia Holze)

2022-03-23T14:26:48+01:00 by Julia Holze

DBpedia, one of InfAI’s community projects, will be part of the 11th Google Summer of Code (GSoC) program. The GSoC program has the goal to bring students from all over the globe into open source software development. Read more about "DBpedia @ Google Summer of Code Program 2022"

DBpedia Tutorial @ The Web Conference 2022 ( 2022-03-16T13:52:16+01:00 by Julia Holze)

2022-03-16T13:52:16+01:00 by Julia Holze

Dear all, We are proud to announce that we will organize an online tutorial at the Web Conference on 25th of April 2022. A particular focus will be put on the DBpedia Infrastructure, i.e. Read more about "DBpedia Tutorial @ The Web Conference 2022"