This function is only available when connected to an Aster database.
The Nth Value function takes two arguments. The first argument is of any type, and the second is an integer that designates the nth row of the partition for which to return the value. The function returns this value as evaluated at the row that is the nth row of the window frame, counting from one (1), in the same type as the first argument. If there is no such row, the function returns NULL. When dragging the Nth Value function into a variable, the following tree is created.
Variable Creation > Input > Variables: SQL Elements pane - Ordered Analytical Functions > Nth Value
