function db_set_active($name = 'seperate_db') {
  global $db_url, $db_type, $active_db;
  static $db_conns;

  if (!isset($db_conns[$name])) {
    // Initiate a new connection, using the named DB URL specified.
    if (is_array($db_url)) {
      $connect_url = array_key_exists($name, $db_url) ? $db_url[$name] : $db_url['default'];
    }
    else {
      $connect_url = $db_url;
    }

    $db_type = substr($connect_url, 0, strpos($connect_url, '://'));
    $handler = "includes/database.$db_type.inc";

    if (is_file($handler)) {
      include_once($handler);
    }
    else {
      die('Unsupported database type');
    }

    $db_conns[$name] = db_connect($connect_url);

  }
  // Set the active connection.
  $active_db = $db_conns[$name];
}