Disappointed to see no pre-google references since the technique was well known to parallel practitioners two decades before it was popularized by google.
@hatetobethatguy, you're spot on. In an effort to keep the reading list concise I skimped on the historical literature. Do you have a good "first" reference on map reduce? Lisp?
I would also love feedback from anybody that's done a good scan of the Impala code or actually put it through its paces.