I think this document is comparing things that are not comparable. They are talking about MapReduce as if it were a distributed database. But that's completely wrong. Hadoop is a distributed computed platform, not a distributed database prepared for OLAP.MapReduce is a re-implementation of LISP's map and reduce in a parallel setting. Now the function/task that you give to Map is where the rubber meets the road of reading data from some data store.
Tuesday, August 12, 2008
Great comment on MapReduce
Spot on comment from Iván de Prado on the Database People Hating on MapReduce blog post.