title: where solr store search index, in database or in file?
body: <p>I am new to Solr. can anybody tell where it stores index.</p>
  
  <ol>
  <li>in existing site database</li>
  <li>create new database</li>
  <li>into xml files.</li>
  </ol>
  
  <p>Thanks in advance</p>
  
  <p><strong>EDIT:</strong> i am asking this because i need a list of files to copy over to production. 
  Suppose, if i index a site on development environment, which files i need to copy over to production environment. we dont want to re-index whole site again when its live.</p>
  
  <p><strong>EDIT-2</strong> where i can find index directory, which stores data folder?</p>