title: PIG: Receiving error while grouping
body: <p>I have a bag called Ftel. <code>describe Ftel;</code> results in following -</p>
  
  <pre><code>Ftel: {billVal:int, billCount:int}
  </code></pre>
  
  <p>An example of dump from Ftel is -</p>
  
  <pre><code>(20,1)
  (5,1)
  (5,1)
  (10,1)
  ...
  etc.
  </code></pre>
  
  <p>I grouped the above bag using the command <code>Gtel = group Ftel by billVal;</code></p>
  
  <p>Now, <code>Dump Gtel;</code> throws following error -</p>
  
  <h2>Pig Stack Trace</h2>
  
  <pre><code>ERROR 1066: Unable to open iterator for alias Gtel
  
  org.apache.pig.impl.logicalLayer.FrontendException: ERROR 1066: Unable to open iterator for alias Gtel
  at org.apache.pig.PigServer.openIterator(PigServer.java:765)
  at org.apache.pig.tools.grunt.GruntParser.processDump(GruntParser.java:615)
  at    
  org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.java:303)
  at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:168)
  at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:144)
  at org.apache.pig.tools.grunt.Grunt.run(Grunt.java:76)
  at org.apache.pig.Main.run(Main.java:455)
  at org.apache.pig.Main.main(Main.java:107)
  Caused by: java.io.IOException: Job terminated with anomalous status FAILED
  at org.apache.pig.PigServer.openIterator(PigServer.java:755)
  </code></pre>
  
  <p>I don't know what is causing this issue. Please help.</p>
  
  <p>Thanks!</p>