title: Solr commit and optimize questions
body: <p>I have a classifieds website. Users may put ads, edit ads, view ads etc.</p>
  
  <p>Whenever a user puts an ad, I am adding a document to Solr.
  I don't know, however, when to commit it. Commit slows things down from what I have read.</p>
  
  <p>How should I do it? Autocommit every 12 hours or so?</p>
  
  <p>Also, how should I do it with optimize?</p>