I have a number of CSV files over which I would like to do SPARQL queries, without converting them to RDF first. I'm trying to figure out how to extend Jena so that each flat file would appear to ARQ queries as a new named graph. This page:
http://jena.sourceforge.net/ARQ/arq-query-eval.html suggests extending GraphBase.java, which is straightforward enough, but it doesn't explain how to register the new Graph implementation with the system. It seems to me that, at a minimum, I would need some way to inform query execution of the named graphs that my extension supplies. Are there any examples of such an extension? I know about ARQ-2.8.8/src-examples/arq/examples/engine/MyQueryEngine.java, but I'm not sure that I need to write my own query engine. I've also been looking at the TDB initialization code. Thanks. --glenn
