I hear a lot about map/reduce, especially in the context of
Google's massively parallel compute system. What exactly is it?
From the abstract of Google's MapReduce research publication
page: The advantage of MapReduce is that the processing can be
performed in parallel on multiple processing nodes (multiple
servers) so it is a system that can scale very well. Since it's
based from the functional programming model, the Joel's Can Your
Programming Language Do This? piece discusses how understanding
functional programming was essential in Google to come up with
MapReduce, which powers its search engine. It's a very good read
if you're unfamiliar with functional programming and how it
allows scalable code. See also: Wikipedia: MapReduce Related
question: Please explain mapreduce simply Map is a function that
applies another function to all the items on a list, to produce
another list with all the return values on it. (Another way of
saying "apply f to x" is "call f, passing it x". So sometimes it
sounds nicer to