title: mapreduce, sort values
body: <p>I have an ouput from my mapper:</p>
  
  <pre><code>Mapper: KEY, VALUE(Timestamp, someOtherAttrbibutes)
  </code></pre>
  
  <p>My Reducer does recieve:</p>
  
  <pre><code>Reducer: KEY, Iterable&lt;VALUE(Timestamp, someOtherAttrbibutes)&gt;
  </code></pre>
  
  <p>I want <code>Iterable&lt;VALUE(Timestamp, someOtherAttrbibutes)&gt;</code> to ordered by <strong>Timestamp</strong> attribute. Is there any possibility to implement it?</p>
  
  <p>I would like to avoid manual sorting inside Reducer code. <a href="http://cornercases.wordpress.com/2011/08/18/hadoop-object-reuse-pitfall-all-my-reducer-values-are-the-same/" rel="nofollow">http://cornercases.wordpress.com/2011/08/18/hadoop-object-reuse-pitfall-all-my-reducer-values-are-the-same/</a></p>
  
  <p>I'll have to "deep-copy" all objects from Iterable and it can cause huge memory overhead. :(((</p>