Exploring a SPARQL endpoint by Bob DuCharme.
From the post:
In the second edition of my book Learning SPARQL, a new chapter titled “A SPARQL Cookbook” includes a section called “Exploring the Data,” which features useful queries for looking around a dataset that you know little or nothing about. I was recently wondering about the data available at the SPARQL endpoint http://data.semanticweb.org/sparql, so to explore it I put several of the queries from this section of the book to work.
An important lesson here is how easy SPARQL and RDF make it to explore a dataset that you know nothing about. If you don’t know about the properties used, or whether any schema or schemas were used and how much they was used, you can just query for this information. Most hypertext links below will execute the queries they describe using semanticweb.org’s SNORQL interface.
…
Bob’s ease at using SPARQL reminds me of a story of an ex-spy who was going through customs for the first time in years. As part of that process, he accused a customs officer of having memorized print that was too small to read easily. The which the officer replied, “I am familiar with it.” 😉
Bob’s book on SPARQL and his blog will help you become a competent SPARQL user.
I don’t suppose SPARQL is any worse off semantically than SQL, which has been in use for decades. It is troubling that I can discover dc:title but have no way to investigate how it was used by a particular content author.
Oh, to be sure, the term dc:title makes sense to me, but that is a smoothing function as a reader and may or may not be the same “sense” as occurs to the person who completed such a term.
You can read data sets using your own understanding of tokens but I would do so with a great deal of caution.