title: How to search documents by version?
body: <p>Is it possible to search documents in Elastic Search index by version? I try this:</p>
  
  <pre><code>curl -XGET eshost:9200/myindex/mytype/_search -d '{query:{match:{_version:"2"}}}'
  </code></pre>
  
  <p>But it does not work. </p>
  
  <p>I need such a query to get all documents, that have never been updated. </p>