title: Using default value for Solr field boosting when field does not exist
body: <p>My existing Solr 4.x instance has about 650k documents indexed. I just added a new field to the schema that will hold a number of votes given to the document that will be used in boosting the score. Until the first user up votes (or down votes) a given document, said document will not have that field defined. You can see this when viewing the document using the Solr Admin tool.</p>
  
  <p>The field was defined with a default value but I <strong>think</strong> this only applies to new documents (or maybe reindexed documents) that do not have said field specified.</p>
  
  <p>When I try to test out different boosting functions, I get the following exception back</p>
  
  <pre><code>  "error": {
      "msg": "can not use FieldCache on a field which is neither indexed nor has doc values: votes",
      "code": 400
    }
  </code></pre>
  
  <p>Is it possible to specify a default <strong>value</strong> to be used for boosting when the field does not (yet) exist in the document? My logic would be</p>
  
  <ul>
  <li>field <em>exists</em> -- use <strong>field</strong> value</li>
  <li>field <em>does not exist</em> -- use <strong>default</strong> value</li>
  </ul>