title: How to remove duplicate columns after a JOIN in Pig?
body: <p>Let's say I <code>JOIN</code> two relations like:</p>
  
  <pre><code>-- part looks like:
  -- 1,5.3
  -- 2,4.9
  -- 3,4.9
  
  -- original looks like:
  -- 1,Anju,3.6,IT,A,1.6,0.3
  -- 2,Remya,3.3,EEE,B,1.6,0.3
  -- 3,akhila,3.3,IT,C,1.3,0.3
  
  jnd = JOIN part BY $0, original BY $0;
  </code></pre>
  
  <p>The output will be:</p>
  
  <pre><code>1,5.3,1,Anju,3.6,IT,A,1.6,0.3
  2,4.9,2,Remya,3.3,EEE,B,1.6,0.3
  3,4.9,3,akhila,3.3,IT,C,1.3,0.3
  </code></pre>
  
  <p>Notice that <code>$0</code> is shown twice in each tuple. EG:</p>
  
  <pre><code>1,5.3,1,Anju,3.6,IT,A,1.6,0.3
  ^     ^
  |-----|
  </code></pre>
  
  <p>I can remove the duplicate key manually by doing:</p>
  
  <pre><code>jnd = foreach jnd generate $0,$1,$3,$4 ..;
  </code></pre>
  
  <p>Is there a way to remove this dynamically? Like <code>remove(the duplicate key joiner)</code>.</p>