Frequently Asked Questions

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How well does it perform/scale?

As with Jena, (which RDQLPlus makes heavy use of) a lot of that depends on your database. There is a practical limit to inference models because they're stored in memory. But where you will likely run into problems first with RDQLPlus is in drawing RDF graphs with a lot of statements. On a modern machine, it only takes a few seconds to draw a couple hundred statements. After that, things get slow very quickly. Don't expect to get much more than a couple thousand statements in one drawing.

Does RDQLPlus support my favorite RDF query language?

If your favorite RDF query language is RDQL, then yes! There are currently no plans to support any other RDF query language.

What kind of computing environment will RDQLPlus run on?

I've had success on Windows 2000, XP and Mac OSX. But you should be able to run it on any Windows or Unix-based machine with an 800x600+ monitor, 64MB+ RAM, a Java 1.4 JRE, and a GraphViz 1.10 "dot" executable.

What version of Jena does RDQLPlus use?

Jena v2.1


Why do I get an error about relative URIs?

This probably means that you're trying to use some RDF that uses relative URIs (starting with #), but you don't have an xml:base defined. RDQLPlus doesn't have a setting for a "default" or per-model base URI, so you have to make sure the RDF you use with it is standalone.

What does "the statements involved in a query" really mean?

All the statements where at least part of the statement matches the WHERE clause and boolean conditions. In most cases, this is more than you're actually asking for from a query. RDQLPlus doesn't support any other method of coming up with a sub-graph at this time.
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