title: how to use pyspark to read orc file
body: <p>there are two types compress file format for spark. one is parquet, it's very easy to read:</p>
  
  <pre><code>from pyspark.sql import HiveContext
  hiveCtx = HiveContext(sc)
  hiveCtx.parquetFile(parquetFile)
  </code></pre>
  
  <p>but for ocr file. I cannot find a good example to show me how to use pyspark to read. </p>