Earning Points. Starwood's Preferred Guest program is fairly straightforward: the more nights you spend at participating hotels, the faster you'll earn a free night.
As seen in the EXECUTING phase, the map will write (using Mapper.Context.write()) its output into a circular in-memory buffer (MapTask.MapOutputBuffer). The size of this buffer is fixed and determined by the configuration parameter mapreduce.task.io.sort.mb (default: 100MB).
Output streams (class ostream and related classes) have some useful member functions for controlling output formatting. Note that these can be used not only with cout, but with other types of output streams. (We'll learn about file output streams soon). setf() -- the set flags function.