Function module based Datasource

Question

Gurus
I am working on creating a function module based extractor. Found some good documents for the same but wanted to check a few things:
u2022     What I understood, I need to copy the function group RSAX as a Z function group. Wanted to check if this needs to be done every time a new FM is written or can I reuse an existing one function group.
u2022     My extractor is on CDPOS and EKPO and I intend to use the FM RSAX_BIW_GET_DATA_SIMPLE. Is this ok or is better to use the RSAX_BIW_GET_DATA or it does not matter.
u2022     I will have to load the historical data for the past one year and then either do a delta or do loads with selection criteria. The user does not have any preference, as currently they only need the report for the last month. But wanted to check which will be a better approach- to do daily deltas or do a periodic (monthly load) with a selection.
Also, wanted to check this is the best approach (having function module) for creating generic DS or is there something else also.
Thanks,
AK

Answer 1

Hi,
u2022 What I understood, I need to copy the function group RSAX as a Z function group. Wanted to check if this needs to be done every time a new FM is written or can I reuse an existing one function group.
You can reuse the existing or newly created group, you don't need to create function group every time you create a FM
Even you don't need to create new function group also, you can simply use the type pool used in RSAX.
u2022 My extractor is on CDPOS and EKPO and I intend to use the FM RSAX_BIW_GET_DATA_SIMPLE. Is this ok or is better to use the RSAX_BIW_GET_DATA or it does not matter.
You can use RSAX_GET_DATA_SIMPLE.
u2022 I will have to load the historical data for the past one year and then either do a delta or do loads with selection criteria. The user does not have any preference, as currently they only need the report for the last month. But wanted to check which will be a better approach- to do daily deltas or do a periodic (monthly load) with a selection.
Actually if you do a daily extraction then data volume will be less compared to if you do a monthly extraction. So you can decide based on no. of records which are getting created/changed daily
Also, wanted to check this is the best approach (having function module) for creating generic DS or is there something else also.
If you simply want to extract data from these two fields then you can create a view on top of these two tables and then create a generic extractor based on view. So you need not do any coding *
Regards,
Durgesh.