Median
Description
Returns the median of all the values in the specified attribute, which is equivalent to sorting all the values and picking the value in the middle. If there is an even number of values, the mean of the two middle values is returned.
Syntax
Median ( n )
Arguments
n is a numeric or temporal expression.
Example
This query returns the median of each continent's female population.
select median(pop_fem), continent from countries group by continent
Remarks
See also http://en.wikipedia.org/wiki/Median.