Code:

$pdoParams = array(
    PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => true
);

$params = array(
    'host'           => '127.0.0.1',
    'username'       => 'webuser',
    'password'       => 'xxxxxx',
    'dbname'         => 'test',
    'driver_options' => $pdoParams
);

$db = Zend_Db::factory('Pdo_Mysql', $params);

// Stored procedure returns a single row
$stmt = $db->prepare('CALL get_customer_by_id(:customerId)');
$stmt->bindParam('customerId', $customerId, PDO::PARAM_INT);
$stmt->execute();
$result = $stmt->fetchAll();
print_r($result);

$stmt->closeCursor();

// Stored procedure returns a single row
$stmt = $db->prepare('CALL get_address_by_id(:customerId)');
$stmt->bindParam('customerId', $customerId, PDO::PARAM_INT);
$stmt->execute();
$result = $stmt->fetchAll();
print_r($result);

This will consistently throw this error: 'SQLSTATE[HY000]: General error:
2014 Cannot execute queries while other unbuffered queries are active.
Consider using PDOStatement::fetchAll(). Alternatively, if your code is only
ever going to run against mysql, you may enable query buffering by setting
the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.'

If you insert $stmt->nextRowset(); before $stmt->closeCursor(); it will
throw this error: 'SQLSTATE[HYC00]: Optional feature not implemented'

This appears to be a bug, and I haven't found any more info as to its status
lately. Is this correct??