title: Can't access JDBC driver through spark with AWS EMR instance
body: <p>I have installed the postgresql driver package when I run spark-shell after I have ssh'ed into the EMR <code>spark-shell --packages org.postgresql:postgresql:9.4-1206-jdbc42</code>. I then import org.postgresql. I want to create a spark Dataframe object, so I try to access a table from  an s3 instance. </p>
  
  <p><code>sqlContext.load("jdbc", Map("url" -&gt; "jdbc:postgresql://pathto.table.region.rds.amazonaws.com:5432/table?user=username&amp;password=password","dbtable" -&gt; "table"))</code></p>
  
  <p>this gives me a <code>java.sql.SQLException: No suitable driver</code> error. </p>
  
  <p>I have looked into <a href="https://stackoverflow.com/questions/32854717/on-amazon-emr-4-0-0-setting-etc-spark-conf-spark-env-conf-is-ineffective">this</a> question with a similar problem. But I want to be able to run the driver through spark-shell. </p>