title: sunspot_solr stored fields
body: <p>I have this line in searchable block</p>
  <pre><code>text :title, :stored =&gt; true
  </code></pre>
  <p>Am searching book title via sunspot solr. But do I really have to use stored field ?</p>
  <pre><code>:stored =&gt; true
  </code></pre>
  <p>as per documentation</p>
  <blockquote>
  <p>Stored fields allow data to be retrieved without also hitting the underlying database (usually an SQL server). They are also required for highlighting and more like this queries.</p>
  <p>Stored fields come at some performance cost in the Solr index, so use them wisely.</p>
  </blockquote>
  <p>But I don't know when should I really use these stored fields. Because I have so many fields in searchable block. Should I make all of them as stored to avoid hitting db ? and what will be the performance cost ?</p>