I saw that one of the requirements to use CompositeInputFormat is: "A map-side join can be used to join the outputs of several jobs that had the same number of reducers, the same keys, and *output files that are not splittable (by being smaller than an HDFS block, or by virtue of being gzip compressed, for example)*"
So Does my partitions size must be equal or smaller than the HDFS Block? If i have a 1 GB File = 1024 mb, i will have 16 partitions of 64 MB? How can i control the size of the partition?
