title: Solr: setting useCompoundFile to be true doesn't have any effect on the index files
body: <p>In SolrConfig.xml, i set below:</p>
  
  <pre><code>&lt;useCompoundFile&gt;true&lt;/useCompoundFile&gt;
  </code></pre>
  
  <p>But once i reindex my stuff, i still see a bunch of index files ranged from _0* to _9*, instead of seeing a single index file.</p>
  
  <p>Question:</p>
  
  <pre><code>1. how to fix this?
  2. if i update index at the run time, is it ok to use compound index then?
  </code></pre>
  
  <p>Thanks!</p>