Hoi Xue Bin
This is no working I´m afraid . As I understand it this will change the amount of the date in the past and is not resulting for an estimated amount in the future.
What I mean is this:
Value in the past on 1-7-2011 50 customers
Estimated value in the future on 1-7- 2012 should be 50 customers *1.5 = 75 customers
Maybe you can try to add a prediction table when you are loading your data. Hope this can solve your problem. Not very sure what you are trying to do though. Are you doing some trend analysis?
LOAD * INLINE [
AddMonths(Date,12) AS PredictDate,
Customer*1.5 AS PredictCustomer
Drop Table tempTable;