Performance in

Hi I am not much familiar with ABAP. I want to populate around 8 key figures in a cube and have hence written a start routine in the update rules. I have around 1.5 million records coming into BW and the code I have written needs to go through 1.5 million times since it has to put the key figure value in all the 1.5 million records. Hence the data load is taking long time.

Can someone suggest me a better approach to populate these keyfigures? Any advice is highly appreciated.

Thanks