You are currently browsing the category archive for the 'SPARQL' category.
This is an awesome little service that my colleague Derek Baron pointed me to.
I’m constantly forgetting what the namespace is for a given prefix in RDF. This little service lets you type in the prefix that you need and gives you back the namespace that you were looking for.
Try these examples. If you look at the source, you will see it is very easy to use in your own tools.
http://prefix.cc/foaf,dc,owl.ttl
If you add the .sparql extension, it will give you back a valid SPARQL query all ready to edit.
http://prefix.cc/rdf,rdfs,owl,dc,foaf,skos.sparql
If you want to get just the plain text for you tool, you can add .plain to the format.
http://prefix.cc/rdf,rdfs,owl,dc,foaf,skos.sparql.plain
And you get back this nicely formatted SPARQL query in plain text (no html tags).
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
SELECT *
WHERE {
?s ?p ?o .
}
Amazon announced recently that their EC2 customers can now access a number of public datasets including the DBPedia which contains 274 million RDF triples. This is very cool news. Provides a great cloud based resource for semantic reasoning over this public data, and the ability to incorporate it into your own custom applications.
Here’s just a few of the public data sets that are now available on Amazon web services.
DBpedia Knowledge Base provided by DBpedia.
DBpedia is a community effort to extract structured information from Wikipedia and to make this information available on the Web. The DBpedia knowledge base currently describes more than 2.6 million things, including at least 213,000 persons, 328,000 places, 57,000 music albums, 36,000 films, 20,000 companies. The knowledge base consists of 274 million pieces of information (RDF triples).
Freebase Data Dump provided by Freebase.com.
A data dump of all the current facts and assertions in the Freebase system. Freebase is an open database of the world’s information, covering millions of topics in hundreds of categories.
Wikipedia Extraction (WEX) provided by Freebase.com.
The Freebase Wikipedia Extraction (WEX) is a processed dump of the English language Wikipedia.
Check out the Amazon site for more details on the public databases: http://aws.amazon.com/publicdatasets/
Also it is interesting to note that the DBPedia folks recently announced links into the Freebase database that are referenced in their own RDF triples. These links show up as RDF triples that use the OWL SameAs property like this:
http://dbpedia.org/resource/Woody_Allen owl:sameAs http://rdf.freebase.com/ns/guid.9202a8c04000641f800000000004064f
These new links are provided in the 3.2 version of the DBPedia, which you can play around with directly using their SPARQL query endpoint located at http://dbpedia.org/sparql. They also have a richer query interface with sampel SPARQL queries here.
I’ve been working with RDF Gateway from Intellidimension in our solution development for the last couple of years and today they dropped what I believe is a significant enhancement in performance to their already fantastic Semantics.Server solution for storing and retrieving RDF triples in SQL Server 2008. Also new in this release is an update to the SDK that provides an Entity framework on top of the existing SDK. The new Entity framework simplifies the way you work with business entities in your semantic applications. I’ll try to put a longer post together later that show how these technologies are used.
The BBC announced yesterday that they are now testing a new Music knowledge base service that aggregates content from the open source DBPedia and other sources.
This is very exciting from my perspective, since my team has been working with Semantic Web technologies (RDF, OWL, SPARQL) for the last couple years to solve problems in the Digital Asset Management space.
I strongly believe that the use of open standards and ontologies is the correct approach to the ability to share and interop with metadata on the web and will lead to more connected media and consumer experiences in the future.
