Drupal site 2 database configuration

drupal2_db_config.php

$databases = array (
  'default' =>
  array (
    'default' =>
    array (
      'database' => 'drupal2',
      'username' => 'username',
      'password' => 'password',
      'host' => 'localhost',
      'port' => '',
      'driver' => 'mysql',
      'prefix' => array(
        'default'   => 'drupal2.',
        'users'     => 'drupal1.',
        'sessions'  => 'drupal1.',
        'role'      => 'drupal1.',
        'authmap'   => 'drupal1.',
        'users_roles'   => 'drupal1.',
      ),
    ),
  ),
);