Answer / Shantanu Sharma

To overwrite an existing output file/dir during the execution of a Hadoop MapReduce job, you can set the 'mapred.job.reuse.jobid' configuration property to false before calling Job.waitForCompletion(). Setting this property to false allows the new job to overwrite any previous job with the same ID.

What do sorting and shuffling do?

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Explain about the partitioning, shuffle and sort phase in MapReduce?

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