dfs.ls: backend-independent listing of directoriesavroinput format
equijoinpreserves keys in default reducer- default
backend.parametersless intrusive, hopefully work for more people out of the box - added startup message about important Hadoop settings pointing to a help entry
NA_character_fully supportedmethodsimported explicitly, apparently it's now necessary- outer joins don't force users to return only lists from reducers
hdfs.cmdheuristics are less brittle