Looks like the author's of the "comparison paper" have a new paper out (the byline says Jan 1 2010) titled "MapReduce and Parallel DBMSs: Friends or Foes?" whic

Looks like the author's of the "comparison paper" have a new paper out (the byline says Jan 1 2010) titled "MapReduce and Parallel DBMSs: Friends or Foes?" which seems to take a different approach at characterizing Map/Reduce, but unfortunately the contents are only available for premium members. http://cacm.acm.org/magazines/2010/1/55743-mapreduce-and-parallel-dbmss-friends-or-foes/fulltext http://cacm.acm.org/magazines/2010/1/55743-mapreduce-and-par... Parallel DBMSs excel at efficient querying of large data sets; MapReduce-style systems excel at complex analytics and ETL tasks. Neither is good at what the other does well. Hence, the two technologies are complementary.