i assume results such as this are due various optimizations under the Tungsten rubric (code generation, manual memory management) which rely on the sun.misc.Unsafe api.
We will be writing a deep dive blog post about this in the next week or two to talk more about this idea.
Excellent, I'm glad that the "big data" world is starting to look at database literature in terms of how it does execution, as there is much to be learned.
Most of these systems are extremely inefficient (looking at you Hadoop), when they don't really have to be. Efficient code generation should be table stakes for any serious processing framework IMO.