Understanding SPARQL Rules with the SPIN Statistics View

One of the new features of TopBraid Composer 3.4 is a new view called SPIN Statistics. Whenever this view is open and you run some SPARQL Rules, this will record the execution time of each individual rule. When completed, you can browse the performance characteristics of each rule, grouped by invocations or by the associated class. In the following screenshot, the SPIN rules for OWL 2 RL executed over the pizza ontology are recorded:

According to the statistics in this screenshot, the rule that implements the transitivity of rdfs:subClassOf has taken the largest fraction of the time. This can help identify performance bottlenecks, and may also be useful to understand better what happens inside of the rule engine. The view can be filled incrementally, e.g. to accumulate how certain rules fire over different data sets.