How to change the DEFAULT key-value SEPARATOR of A MAPREDUCE JOB

The default MapReduce output format, Textoutputformat, writes records as lines of text. Its keys and values may is of any type, since Textoutputformat turns them to strings by calling ToString () on them.

Each key-value pair are separated by a tab character. We can change this separator to some character of our choice using themapreduce.output.textoutputformat.separator (in the older MapReduce API this is mapred.textoutputformat.separator).

The to does this your driver function-
Configuration.set ("Mapreduce.output.key.field.separator", ",");

How to change the DEFAULT key-value SEPARATOR of A MAPREDUCE JOB