Reduce
Tuesday, February 23, 2010
6:27 PM
Part 3: Reduce
Create a global view of data from the local views
Combine work from several nodes. 
E.g. if
Node01 handles lines 1 and 5
Node02 handles lines 2 and 6
Node03 handles lines 3 and 7
Node04 handles lines 4 and 8
Then the reduce depicts results for lines 1-8. 
(It is easy enough to produce this in sorted order).