title: NSFetchedResultsController with search
body: <p>What is the best practice to filter the <code>NSFetchedResultsController</code> data?
  do i need to re-initialize it every time the searchbar's text changes?</p>
  
  <p>I am using a <code>UISearchDisplayControllers</code> and i'm implementing:</p>
  
  <pre><code>- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString;
  </code></pre>
  
  <p>Thx.</p>