title: How to find spark RDD/Dataframe size?
body: <p>I know how to find the file size in scala.But how to find a RDD/dataframe size in spark?</p>
  
  <p>Scala:</p>
  
  <pre><code>object Main extends App {
    val file = new java.io.File("hdfs://localhost:9000/samplefile.txt").toString()
    println(file.length)
  }
  </code></pre>
  
  <p>Spark:<br/></p>
  
  <pre><code>val distFile = sc.textFile(file)
  println(distFile.length)
  </code></pre>
  
  <p>but if i process it not getting file size. How to find the RDD size?</p>