title: Is a static file loaded and unloaded for each batch operation in Spark?
body: <p>I am using Spark to perform some operations on my data. 
  I need use a auxiliary dictionary to help my data operations.</p>
  
  <pre><code>streamData = sc.textFile("path/to/stream")
  dict = sc.textFile("path/to/static/file")
  //some logic like:
  //if(streamData["field"] exists in dict)
  // do something
  </code></pre>
  
  <p>My question is: is the dict in memory all the time or does it need to be loaded and unloaded each time Spark is working on a batch?</p>
  
  <p>Thanks</p>