Does map/reduce merge output files after reduce phase?

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Hey everyone. I have a doubt in mapreduce. In mapreduce each reduce task write its output to a file named part-r-nnnnn where nnnnn is a partition ID associated with the reduce task. Does map/reduce merge these files? If yes, how?

Sep 25, 2018 in Big Data Hadoop by slayer
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1 answer to this question.

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Hey there, instead of doing the file merging on your own, you can delegate the entire merging of the reduce output files by calling:

hadoop fs -getmerge /output/dir/on/hdfs/ /desired/local/output/file.txt
answered Sep 25, 2018 by digger
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