Hello, I'm interested in a map-reduce flow where I output only values (no keys) in my reduce step. For example, imagine the canonical word-counting program where I'd like my output to be an unlabeled histogram of counts instead of (word, count) pairs.
I'm using HadoopStreaming (specifically, I'm using the dumbo module to run my python scripts). When I simulate the map reduce using pipes and sort in bash, it works fine. However, in Hadoop, if I output a value with no tabs, Hadoop appends a trailing "\t", apparently interpreting my output as a (value, "") KV pair. I'd like to avoid outputing this trailing tab if possible. Is there a command line option that could be use to effect this? More generally, is there something wrong with outputing arbitrary strings, instead of key-value pairs, in your reduce step?
