Hi Sameer.
Shouldn't be something tough .
Option 1 :
What is your database ? If HANA, then in "copy query" , keep the required characteristics only. i.e
'State' , ShipTo, Month and Division and Key Figure . HANA does aggregation quite fast .
Option 2:
If you are on non-HANA database, and reporting on Cube , create an aggregate on top of cube with required characteristics . Data would be fetched from aggregate instead of the cube if designed properly.
Option 3 : If you have non-HANA database and original report run on DSO, you can create another DSO with required characteristics only ( i.e removing billing number, item etc) . In the transformation from DSO1 to DSO2 , choose Aggregation as the update mode of Key Figure . Load DSO2 from DSO1. All aggregation would be done during load time.
Regards
Anindya