title: Is possible to do a Top Ten and a JOIN in the same job with Hadoop?
body: <p>I have two files: Posts and Users. I need to get the top 10 users by posts, something that in SQL should be:</p>
  
  <pre><code>    SELECT us.name, COUNT(po.id) AS NumberOfPost FROM User us INNER JOIN Post po on
   po.userId = us.id GROUP BY us.name ORDER BY NumberOfPost DESC;
  </code></pre>
  
  <p>There is possible to do this with only one Job? without the need of a Job to make the JOIN and a Job to do the Top Ten? i must follow the mapreduce pattern of "Top Ten" but i don't have to follow any join Pattern in this case. There is a way to do it with one Job only?</p>