How to perform cummulative sum in Mapping
For eg,
Id Amt
1 10
2 20
3 30
The output should be
Id Amt
1 10
2 30
3 60

use CUME(Amt) function

in,expression tranformation ,
use cum(amt) in numeric functions

Cumulative sal in Informtica write the expression t/r

create a variable port : v_cume_sal=v_cume_sal+sal
output port : o_cume_sal=v_cume_sal

or

function cume(sal)

In Expression t/r
Create one variable Port v_cum_sal=v_cuma_sal+sal
output port o_cum_sal=v_cum_sal

Create a variable port : v_cume_sal=v_cume_sal+amt
output port : o_cume_sal=v_cume_sal