On Thu, Jun 9, 2011 at 1:32 AM, Gal Dolber <gal.dol...@gmail.com> wrote: > I am not comparing reflexion vs byte-code generation or anything like that, > apt generates code, is not a runtime technology. > Like or not reflexion is known to be slower than actually writing the code.
This is entirely irrelevant. We've now established that the issue at hand is a strange quirk in the Low-Level API and has nothing to do with reflection. 100% (or close to it) of the performance "gain" of Slim3 is because it calls .size() on a List before iterating it. > Slim3 generates the minimal possible code you need to talk with the low > level api, if the low level bench is faster is just because its not > converting the Entity to the Pojo. You missed the point - in the benchmark, Slim3 was *faster* than the Low-Level API. This clearly indicated something was amiss, and now we've uncovered the actual cause. It turns out to be something quite interesting indeed. This is a classic case of what Feynman called Cargo Cult Science. You all believed that Slim3 should be faster than other APIs because code generation is faster than reflection, so when someone produced an ill-conceived benchmark that seemed to confirm your preconceived notion, you just accepted the entire narrative: "Slim3 is fast because it doesn't use reflection!" This is sloppy thinking (see: Confirmation Bias). If you haven't read this, it's a gem (I make a habit of re-reading it at least once a year): http://www.lhup.edu/~DSIMANEK/cargocul.htm Jeff -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
