Opening a new database connection in Doctrine is very easy. If you wish to use PDO (www.php.net/PDO) you can just initalize a new PDO object:

<code type="php">
$dsn = 'mysql:dbname=testdb;host=127.0.0.1';
$user = 'dbuser';
$password = 'dbpass';

try {
    $dbh = new PDO($dsn, $user, $password);
} catch (PDOException $e) {
    echo 'Connection failed: ' . $e->getMessage();
}
</code>