title: What are the files generated by Spark when using "saveAsTextFile"?
body: <p>When I run a Spark job and save the output as a text file using method "saveAsTextFile" as specified at <a href="https://spark.apache.org/docs/0.9.1/api/core/index.html#org.apache.spark.rdd.RDD" rel="noreferrer">https://spark.apache.org/docs/0.9.1/api/core/index.html#org.apache.spark.rdd.RDD</a> :</p>
  
  <p><img src="https://i.stack.imgur.com/8PuYQ.png" alt="enter image description here"></p>
  
  <p>here are the files that are created : </p>
  
  <p><img src="https://i.stack.imgur.com/VyVjY.png" alt="enter image description here"></p>
  
  <p>Is the .crc file a Cyclic Redundancy Check file ? and so is used to check that the content of each generated file IS correct ?</p>
  
  <p>The _SUCCESS file is always empty, what does this signify ?</p>
  
  <p>The files that do not have an extension in above screenshot contain the actual data from the RDD but why are  many files generated instead of just one ?</p>