Keep an Eye ont this support for Semantic RDF by restlet. I have a feeling that this might be very useful
Running OWL DL reasoning over billions, possibly trillions of highly dynamic triples... hmm... where do you want the 27 PhD theses required to (partially) answer this question delivered? (:P
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The short version is that it's simply not feasible. You will need to make trade-offs, particularly in terms of the expressivity of reasoning. Even then, the answer is not simple.