title: How to combine two RDDs in Spark (Scala)?
body: <p>So, let's say I have the following two RDDS: 
  (These are only the first few rows for each RDD) </p>
  
  <p>RDD1: </p>
  
  <pre><code>Time                   Temp 
  2014-08-12 13:20:00    22
  2014-08-12 13:21:00    24
  2014-08-12 13:24:00    26
  2014-08-12 13:26:00    27
  2014-08-12 13:28:00    22
  </code></pre>
  
  <p>RDD2: </p>
  
  <pre><code>Time                   Age 
  2014-08-12 13:20:00    45
  2014-08-12 13:21:00    45
  2014-08-12 13:24:00    46
  2014-08-12 13:26:00    37
  2014-08-12 13:28:00    122
  </code></pre>
  
  <p>And I would like to combine them such that the column of RDD2 is added to RDD1. I can't use union since that will just add RDD2 to the bottom of  RDD1, whereas I would like to add it to the "side", if that makes sense. </p>