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What Hadoop command would you use to merge multiple files into one?

Spark/Big Datamedium0.5 min readPremium
Frequency
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Asked at 1 company
Category
452
questions in Spark/Big Data
Difficulty Split
88E|81M|283H
in this category
Total Bank
1,863
across 7 categories
Asked at these companies
Infosys
Key Concepts Tested
partitionspark
Expert AnswerPremium
109 wordsInterview-ready
**getmerge** (HDFS to local): `hadoop fs -getmerge /input/dir /local/merged.txt` **In-HDFS merge** (cat + put): `hadoop fs -cat /input/dir/* | hadoop fs -put - /output/merged` **Spark** (preferred for large data): `spark.read.text("/input/*").coalesce(1).write.text("/output")` **Why Avoid Single Huge File**: (1) No parallelism for downstream reads. (2) Single block limits map tasks. (3) Memory pressure if read entirely....
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