title: Unable to use a new SparkSession after stopping the previous one
body: <p>I created a SparkSession (with enabledHiveSupport()) and running locally.
  I want to execute a set of sql's in one SparkSession, stop it and start another.  </p>
  
  <p>But when I stop a SparkSession and get a new one using the SparkSession.builder(), I get a new SparkSession object but the sql fails with "Another instance of Derby may have already booted the database.."</p>
  
  <p>Since we can have one only one SparkContext per JVM, does this mean I cannot getOrCreate SparkSession, stop it and repeat?</p>
  
  <p>Is there any way to execute a set of sql's in a new session every time? (I know there is SparkSession.newSession, though I can't stop that session too as the underlying shared SparkContext will stop, right?)</p>