triplestores

Querying for labels

The normal way and the wikibase:label service way

In my last blog entry I discussed various ways that different RDF datasets assign human-readable labels to resources, with the rdfs:label property being at the center of them all. I mentioned how schema.org doesn’t use rdfs:label but its own equivalent of that, schema:name, which its schema declares as a subproperty of rdfs:label. Since I wrote that, Fan Li pointed out that Facebook’s Open Graph protocol also has their own equivalent: og:title, which you can see used in the HTML…

Human-readable names in RDF

Sometimes simple, sometimes not.

First, reviewing some basics before I discuss the edge cases: resources in RDF are represented by URIs, and the spelling of a given URI often provides no clues about what the URI represents. For example, you wouldn’t know from looking at http://www.wikidata.org/entity/Q144 that it represents “dog” as a Wikipedia topic. (We’ll see below that this is a for a good reason.)

RDF* and SPARQL*

Reification can be pretty cool.

After I posted Reification is a red herring (and you don’t need property graphs to assign data to individual relationships) last month, I had an amusingly difficult time explaining to my wife how that would generate so much Twitter activity. This month I wanted to make it clear that I’m not opposed to reification in and of itself, and I wanted to describe the fun I’ve been having playing with Olaf Hartig and Bryan Thompson’s RDF* and and SPARQL* extensions to these…

IBM's DB2 as a triplestore

Surprisingly easy to set up and use, but requiring lots of Java coding for any real application development.

I thought it was pretty big news for the semantic web world when IBM announced that release 10.1 of their venerable DB2 database manager could function as an RDF triplestore, but it seems that few others—not even, apparently, IBM staff responsible for marketing semantic technology—agreed with me. More on this below.

Playing with SPARQL Graph Store HTTP Protocol

GETting, POSTing, PUTting, and DELETEing named graphs.

One of the new SPARQL 1.1 specifications is the SPARQL 1.1 Graph Store HTTP Protocol, which is currently still a W3C Working Draft. According to its abstract, it “describes the use of HTTP operations for the purpose of managing a collection of graphs in the REST architectural style.” Recent releases of Sesame support it, so I used that to try out some of the operations described by this spec. I managed to do GET, PUT, POST, and DELETE operations with individual named graphs, so that…

Writing about the Semantic Web

And Linked Data, and RDF, and RDFa, and SPARQL, and OWL, and...

After writing a few paid articles and doing a lot of blogging about various issues, features, and trends surrounding the Semantic Web, Linked Data, RDF, RDFa, SPARQL, OWL, and related tools and implementations, I thought it would be nice if I could tie them together into something resembling a cohesive whole. So, I wrote a short essay titled RDF, The Semantic Web, and Linked Data with over 70 footnote links to these various pieces. It will be a handy reference for me in the future, and I hope it…