Please indicate total order quantity of product Geitost and calculate the percentage of such product among all the order quantity.
'Geitost' is a ProductName; calculation = DIVIDE(ProductName = 'Geitost', COUNT(ProductID)) * 100
SELECT SUM(IF(T1.ProductName = 'Geitost', 1, 0)) AS sum , CAST(SUM(IF(T1.ProductName = 'Geitost', 1, 0)) AS REAL) / COUNT(T1.ProductID) FROM Products AS T1 INNER JOIN `Order Details` AS T2 ON T1.ProductID = T2.ProductID