Hi, In reducer-reduce you iterate twice over the values compared to the java version, once in map (just to call .get), then in reduce.
There are other issues probably, but this is one of the obvious ones. On Friday, April 26, 2013 12:05:33 PM UTC+2, Ji Zhang wrote: > > Hi, > > I'm writing map-reduce job with Clojure, yet to find that it seems to be > much slower than a Jave job. > > So I write a simple test case, and upload to gist: > https://gist.github.com/jizhang/5466149 > > At the end of code, there is execution outputs, here are some significant > stats: > > Average time taken by Map tasks: Java 7sec, Clojure 19sec > CPU time spent (ms): Java 244,000, Clojure 1,145,440 > > I'm wondering what slows down the Clojure written map-reduce job. Am I > using it wrong, or it's just an inappropriate senario. > > Any thoughts will be great. Thanks! > > Jerry > -- -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
