title: Add partitions on existing hive table
body: <p>I'm processing a big hive's table (more than 500 billion records).
  The processing is too slow and I would like to make it faster.
  I think that by adding partitions, the process could be more efficient.</p>
  
  <p>Can anybody tell me how I can do that?
  Note that my table already exists.</p>
  
  <p>My table :</p>
  
  <pre><code>create table T(
  nom string,
  prenom string,
  ...
  date string)
  </code></pre>
  
  <p>Partitioning on date field.</p>
  
  <p>Thx</p>