title: Equivalent of linux 'diff' in Apache Pig
body: <p>I want to be able to do a standard diff on two large files. I've got something that will work but it's not nearly as quick as diff on the command line. </p>
  
  <pre><code>A = load 'A' as (line);
  B = load 'B' as (line);
  JOINED = join A by line full outer, B by line;
  DIFF = FILTER JOINED by A::line is null or B::line is null;
  DIFF2 = FOREACH DIFF GENERATE (A::line is null?B::line : A::line), (A::line is null?'REMOVED':'ADDED');
  STORE DIFF2 into 'diff';
  </code></pre>
  
  <p>Anyone got any better ways to do this?</p>