Median is informatica aggregator function which computes mathematical median of input values
Syntax

MEDIAN( numeric_port [, filter_condition ] )

Argument	Required/Optional	Description
numeric_value	Required	Numeric datatype. Passes the values for which you want to calculate a median. You can enter any valid transformation expression.
filter_condition	Optional	Limits the rows in the search. The filter condition must be a numeric value or evaluate to TRUE,

If even number of rows are passed, median returns average of two middle values and for add rows it returns the middle value. [Numbers are sorted in ascending order before the computation]
Note :
Like other aggregate functions, informatica eliminates null values but if all are value, median function returns null.
You can nest one other aggregator function within median function
If no group by port is specified, all the rows considered as a single group.

Example : Find median of given marks for the students who passed the exam

MEDIAN(marks,marks > 50)

Student Name	Marks
Eric	70
Cathy	82
Wayn	65
Rookie	45
Sam	40
Michael	90

Return value : 76