Well, to give more explanation, I normally put:

    'db' => array(
        'driver'         => 'Pdo',
        'driver_options' => array(
            PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES \'UTF8\''
        ),
    ),

in `global.php`, as these are effectively defaults that rarely need to be changed (but could be overridden in `local.php` if necessary). I then put:

    'db' => array(
        'dsn' => 'mysql:dbname=DBNAME;host=localhost',
        'username' => 'xxx',
        'password' => 'xxx'
    ),

in `local.php`, as these are always environment-specific.

If you want to put all the DB stuff in a `local.php` I think that would be better than what we currently have here.