Theoretically nice… practically I’d say there is a fundamental problem with this idea (different than the ones listed in the article). Map and reduce functions are supposed to run on the nodes hosting the data
. If you need to wire this data is like implementing mapreduce on your application so the data locality property is lost. Not to mention that adding another variable to the equation (the JVM) your distributed system will become more sensible to failures.
Original title and link for this post: Riak Map/Reduce Queries in Clojure (published on the NoSQL blog: myNoSQL)