title: Titan graph database: speed up AND and OR gremlin queries using the Indexing backends
body: <p>I have used Titan 1.0 in production. (Cassandra + Solr) I was wondering how can I speed up AND/ OR queries through indexing backend. Suppose mixed index has been defined on "user_info" and "vertex_label" fields. How can I tell Titan to use indexing backend as a source of data preparation for the following query or other similar ones:</p>
  
  <pre><code>g.V().or(__.has("user_info",Text.textRegex("job=Teacher")),
        __.has("vertext_label","user")))
  </code></pre>
  
  <p>I have checked this query using query.force-index=true to see whether it uses any kind of index or not; but the thrown exception showed it didn't.</p>