Calculating Median in Sap Hana

A very nice idea, found at
http://sqlblog.com/blogs/adam_machanic/archive/2006/12/18/medians-row-numbers-and-performance.aspx

SELECT
 CustomerId,
 AVG(TotalDue)
FROM
(
 SELECT
 CustomerId,
 TotalDue,
 ROW_NUMBER() OVER (
 PARTITION BY CustomerId
 ORDER BY TotalDue ASC, SalesOrderId ASC) AS RowAsc,
 ROW_NUMBER() OVER (
 PARTITION BY CustomerId
 ORDER BY TotalDue DESC, SalesOrderId DESC) AS RowDesc
 FROM Sales.SalesOrderHeader SOH
) x
WHERE
 RowAsc IN (RowDesc, RowDesc - 1, RowDesc + 1)
GROUP BY CustomerId
ORDER BY CustomerId