title: Hadoop, how to compress mapper output but not the reducer output
body: <p>I have a map-reduce java program in which I try to only compress the mapper output but not the reducer output. I thought that this would be possible by setting the following properties in the Configuration instance as listed below. However, when I run my job, the generated output by the reducer still is compressed since the file generated is: part-r-00000.gz. Has anyone successfully just compressed the mapper data but not the reducer?  Is that even possible?</p>
  
  <p>//Compress mapper output</p>
  
  <pre><code>conf.setBoolean("mapred.output.compress", true);
  conf.set("mapred.output.compression.type", CompressionType.BLOCK.toString());
  conf.setClass("mapred.output.compression.codec", GzipCodec.class, CompressionCodec.class);
  </code></pre>