CODEWITHSUNDEEP
hadoopapache-pig
kee
kee

Reputation: 11629

Is compression/decompression of gzip data transparent in Hadoop/PIG?

I read somewhere that Hadoop has a built-in support for compression and decompression but I guess it is about mapper output (by setting some properties)?

I wonder if there is any particular PIG load/store functions I can use for reading compressed data or outputting data as compressed?

Upvotes: 1

Views: 2734

Answers (1)

Chris White
Chris White

Reputation: 30089

The PigStorage handles compressed input by examining the file names:

  • *.bz2 / *.bz - org.apache.pig.bzip2r.Bzip2TextInputFormat
  • Everything else uses org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigTextInputFormat -- This extends o.a.h.mapreduce.TextinputFormat which can handle .gz and zippy files if you have the codecs installed

Output is handled via some properties:

  • output.compression.enabled - true / false
  • output.compression.codec - the class name of the codec to use (org.apache.hadoop.io.compress.GzipCodec for gzip)

If you're feeling up to it, digging through the PigStorage.java may be of interest to you

Upvotes: 6

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