how to merge reduce task output to produce final output file?

[#1]

i am using hive editor ,

in mapreduce job, map task output will be combined and reduce phase will take this output as a input. By default each reducer will generate a separate output file like part-0000 and this output will be stored in HDFS.

• 1)After completion of reduce task , which process will be done for combining reduce phase output to produce final output in hive editor and where?

[#2]

You can set hive.merge.mapredfiles to true , it will run the another mapreduce job after the original one to combine all files into one.

https://cwiki.apache.org/confluence/display/Hive/AdminManual+Configuration