title: Is there an efficient way to process data expiration / massive deletion (to free space) with Riak on leveldb?
body: <p>On Riak :</p>
  
  <ol>
  <li>Is there a way to process <strong>data expiration</strong> or to dump old data to <strong>free some space</strong>?</li>
  <li><strong>Is it efficient ?</strong></li>
  </ol>
  
  <p>Edit: Thanks to Joe to provide the answer and its workaround (answer down).
  Data expiration should be thought from the very beginning as it requires an additional index with a map-reduce algorithme.</p>