title: Prebuilt Spark 2.1.0 creates metastore_db folder and derby.log when launching spark-shell
body: <p>I just upgraded from Spark 2.0.2 to Spark 2.1.0 (by downloading the prebuilt version for Hadoop 2.7&amp;later). No Hive is installed.</p>
  
  <p>Upon launch of the spark-shell, the <code>metastore_db/</code> folder and <code>derby.log</code> file are created at the launch location, together with a bunch of warning logs (which were not printed in the previous version).</p>
  
  <p>Closer inspection of the debug logs shows that Spark 2.1.0 tries to initialise a <code>HiveMetastoreConnection</code>: </p>
  
  <p><code>
  17/01/13 09:14:44 INFO HiveUtils: Initializing HiveMetastoreConnection version 1.2.1 using Spark classes.
  </code></p>
  
  <p>Similar debug logs for Spark 2.0.2 do not show any initialisation of <code>HiveMetastoreConnection</code>.</p>
  
  <p>Is this intended behaviour? Could it be related to the fact that <code>spark.sql.warehouse.dir</code> is now a static configuration shared among sessions? How do I avoid this, since I have no Hive installed?</p>
  
  <p>Thanks in advance!</p>