Hadoop - set reducer number to 0 but write to same file? <p>My job is computational intensive so I am actually only using the distribution function of Hadoop, and I want all my output to be in 1 single file so I have set the number of reducer to 1. My reducer is actually doing nothing...</p> <p>By explicitly setting the number of reducer to 0, may I know how can I control in the mapper to force all the outputs are written into the same 1 output file? Thanks. </p>