title: Implicit Cast Warning
body: <p>When I run my pig script, I have a lot of</p>
  
  <pre><code>Encountered Warning IMPLICIT_CAST_TO_LONG ... time(s).
  Encountered Warning IMPLICIT_CAST_TO_FLOAT ... time(s).
  Encountered Warning IMPLICIT_CAST_TO_DOUBLE ... time(s).
  </code></pre>
  
  <p>I was wondering under what circumstance PigServer will emit these warnings and whether these implicit castings will slow down the process?</p>
  
  <p>Thanks!</p>