title: Solr - Data Import Handler - Full Import - Clean=False by default?
body: <p>Version: apache-solr-3.5.0</p>
  
  <p>For full imports, you can set a url param clean=false.</p>
  
  <p>However, can 'clean' be set to 'false' as a default, somewhere like the XML configs, or something?</p>
  
  <p>If not, can full imports be disabled in any way?</p>
  
  <p>Thanks!</p>