Does Hadoop merge the output files after reduce phase

–1 vote
I am running a mapreduce task and I want to output files to be merged as a single file. Does Hadoop merge the files after the reduce phase? If not, how can I merge the files?
Jan 23, 2019 in Big Data Hadoop by digger
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1 answer to this question.

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No, the files after the reduce phase are not merged by Hadoop. The number of files you get is the same as the number of reduce tasks. To merge the files manually, you can use the following command:

hadoop fs -getmerge /output/dir/on/hdfs/ /desired/local/output/file.txt

answered Jan 23, 2019 by Omkar
• 69,190 points

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