Write SQL query to solve given problem: Please indicate total order quantity of product Geitost and calculate the percentage of such product among all the order quantity.. Keep the solution inside sql tag ```sql [SQL-Query] ```
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