title: Generating all fields from an alias after a JOIN in Pig
body: <p>I would like to perform the equivalent of "keep all <code>a</code> in <code>A</code> where <code>a.field == b.field</code> for some <code>b</code> in <code>B</code>" in Apache Pig.  I am implementing it like so,</p>
  
  <pre><code>AB_joined = JOIN A by field, B by field;
  A2 = FOREACH AB_joined GENERATE A::field as field, A::field2 as field2, A::field3 as field3;
  </code></pre>
  
  <p>Enumerating all of <code>A</code>'s entries is quite silly, and I would rather do something like,</p>
  
  <pre><code>A2 = FOREACH AB_joined GENERATE flatten(A);
  </code></pre>
  
  <p>However, this doesn't seem to work.  Is there some other way I can do something equivalent without enumerating <code>A</code>'s fields?</p>