Incremental loading for fact table in informatica

Question

I am performing SCD type 1 mapping. I have these source tables.

1.CUSTOMERS, (Source customer File)
2.PRODUCTS (Source Product File)
3.SALES   (source Sales file)

Also, these are dimensions and fact tables.

1.D_CUSTOMERS (SCD 1),
2.D_PRODUCTS (SCD 1) and
3.F_SALES_DLY (Fact)

Sales contains daily level data. Fact table will have sales & quantity data aggregated for product & for a month.(Fact table should be incremental for 24 months.(It should always contain 24 months of data)

I am bit confused, How to make fact table incremental? If i try to use any transformation(filter) to get last 24 months records, is it feasible solution?

Please suggest me something..

Thanks...

Answer 1

One way to implement it is split the task into two steps: (1) create a mapping that will delete transactions older than 24 months, (2) create a second mapping to get the transactions for the last 24 months from SALES, aggregate it and then insert the new values and update the existing ones.