to the MySQL server providing the ability to:
* calculate the median of any values,
* calculate the skewness and kurtosis of a distribution of value
* retrieve the effective length of the longest value in a STRING column,
* get the longest value from a STRING column,
* calculate the faculty of a value,
* calculate linear regression parameters (intercept, slope, correlation
coefficent) of any values
WWW: http://mysql-udf.sourceforge.net/