title: Sphinx, ranking by words count
body: <p><br/>
  I use a sphinx as fulltext search engine, and ranker option is set to <strong>proximity</strong>.
  <br> How can I set as ranker this formula: <strong>proximity</strong> + <strong>count of words in <em>somecolumn</em></strong> / <strong>hit_count</strong>?<br/></p>
  
  <p>I don't know, how can I get words count. <br/>
  I've tried to add a column with count of words into the index, but <strong><em>somecolumn</em></strong> is a huge concate field, and I can't use <a href="https://stackoverflow.com/a/9920337/2254668">this example</a>, because it will be too slow query.</p>