I am playing around with MapReduce and wanted to ask why the
map function takes two inputs
(key, value)? Why not just pass along the value?
Specifically, if you look at the word count example on Wikipedia page you will see that the map function is:
function map(String name, String document): // name: document name // document: document contents for each word w in document: emit (w, 1)
However, the function never does anything with the parameter "name". Why even pass it in?