require_once 'MDB2.php';

$dsn = 'pgsql://someuser:apasswd@localhost/thedb';
$options = array(
    'debug' => 2,
    'result_buffering' => false,
);

$mdb2 = MDB2::connect($dsn, $options);
if (PEAR::isError($mdb2)) {
    die($mdb2->getMessage());
}

// ...

$mdb2->disconnect();