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…

I recently tweeted that the ZDNet article Back to the future: Does graph database success hang on query language? was the best overview of the graph database world(s) that I’d seen so far, and I also warned that many such “overviews” were often just Neo4j employees plugging their own product. (The Neo4j company is actually called Neo Technology.) The most extreme example of this is the free O’Reilly book Graph Databases, which is free because it’s being given away…

Amazon recently announced Neptune as an AWS service. As its home page describes it,

Last month, in The W3C standard constraint language for RDF: SHACL, I described the history of this new standard that lets us define constraints on RDF data and an open source tool that lets us identify where such constraints were violated. The presence of the standard and tools that let us implement the standard will be a big help to the use of RDF in production environments.

Last month I promised that I would dig further into the Wikidata data model, its mapping to RDF, and how we can take advantage of this with SPARQL queries. I had been trying to understand the structure of the data based on the RDF classes and properties I saw and the documentation that I could find, and some of the vocabulary discussing these issues confused me–for example, RDF is about describing resources, but I was seeing lots of references to entities, which can mean slightly different…

When I wrote the blog posting My SQL quick reference last month, I showed how you can pass an SQL query to MySQL from the operating system command line when starting up MySQL, and also how adding a -B switch requests a tab-separated version of the data. I did not mention that -X requests it in XML, and that this XML is simple enough that a fifteen-line XSLT 1.0 spreadsheet can convert any such output to RDF.

When I first heard about Albert Meroño-Peñuela and Rinke Hoekstra’s midi2rdf project, which converts back and forth between the venerable Musical Instrument Digital Interface binary format and RDF, at first I thought it seemed like an interesting academic exercise. Thinking about it more, I realized that it makes a great contribution to both the MIDI world and to musical RDF geeks.