title: How to uncache RDD?
body: <p>I used <code>cache()</code> to cache the data in memory but I realized to see the performance without cached data I need to uncache it to remove data from memory:</p>
  
  <pre><code>rdd.cache();
  //doing some computation
  ...
  rdd.uncache()
  </code></pre>
  
  <p>but I got the error said: </p>
  
  <blockquote>
    <p>value uncache is not a member of org.apache.spark.rdd.RDD[(Int, Array[Float])]</p>
  </blockquote>
  
  <p>I don't know how to do the uncache then!</p>