Actually it should be rdd.reduceByKey(_ ++ _) On Mar 3, 2014, at 11:56, Andrew Ash <and...@andrewash.com> wrote:
> rdd.reduceByKey(_+_) using list concatenation? > > Sent from my mobile phone > > On Mar 2, 2014 7:05 PM, "David Thomas" <dt5434...@gmail.com> wrote: > I have an RDD of (K, Array[V]) pairs. > > For example: ((key1, (1,2,3)), (key2, (3,2,4)), (key1, (4,3,2))) > > How can I do a groupByKey such that I get back an RDD of the form (K, > Array[V]) pairs. > > Ex: ((key1, (1,2,3,4,3,2)), (key2, (3,2,4)))