title: Creating many, short-living SparkSessions
body: <p>I've got an application that orchestrates batch job executions and I want to create a <code>SparkSession</code> per job execution - especially in order to get a clean separation of registered temp views, functions etc.</p>
  
  <p>So, this would lead to thousands of SparkSessions per day, that will only live for the duration of a job (from a few minutes up to a several hours). Is there any argument to not do this ?</p>
  
  <p>I am aware of the fact, that there is only one <code>SparkContext</code> per JVM. I also know that a <code>SparkContext</code> performs some JVM global caching, but what exactly does this mean for this scenario ? What is e.g. cached in a <code>SparkContext</code> and what would happen if there are many spark jobs executed using those sessions ? </p>