Extraction, Flat File, Generic Data Source, Delta Initialization

Question

Extraction, Flat File, Generic Data Source, Delta Initialization
I have couple of questions regarding data extraction.
1.     If you have Data Source a Flat File e.g. Excel file I know that you have to create Data Source at BW side. How do you upload updates, by selecting Delta Update when executing next Data Load? Do you ever u201Cconvertu201D this Excel file into Application Tables to become SAP Source 
2.     Can you please give me example of situation where you had to create Generic Data Source? What is difference between Time Stamp, Calend. Day and Numeric Pointer. Which one is most common to select?
3.     I read somewhere that Generic Data Source does not have Setup Table. I thought that you have to have Setup Table in order to load transaction Data otherwise you will lock the Application Tables. Where am I going wrong im my thinking please?
4.     What are steps in terms of IP before, under and after Delta Initialization. I belive that you can do two ways:
Full Update - Initialize Delta Process (without Data Transfer) u2013 Delta Update  or
Initialize Delta Process (with Data Transfer) u2013 Delta Update
Am I right? What is most common method and why?
5.     If you want to add a filed in Data Source after 6 month using it, you want to do it without re-init Delta Queue. You add field in RSA6, then provide info for ABAP to populate new filed (info u2013 name of Data Source, Extract Structure, field added, name of Application Table which contains the field). How does it work now as there is no SetUp table it has been deleted after Initialisation? How does Delta Queue know that it is going to receive data which has been  expanded by one field or it may does not need to know at all?
THANKSSSSSSSSSs

Answer 1

Hi,
1. If you have Data Source a Flat File e.g. Excel file I know that you have to create Data Source at BW side. How do you upload updates, by selecting Delta Update when executing next Data Load? Do you ever u201Cconvertu201D this Excel file into Application Tables to become SAP Source
Once you create Datasource for A flat file extraction then it is file source system specific hence you cont change to Application table source Data source
In info package you can change the source as application server instead of desktop no need to change the DS
2. Can you please give me example of situation where you had to create Generic Data Source? What is difference between Time Stamp, Calend. Day and Numeric Pointer. Which one is most common to select?
When we don't find any standard extractor then we can go for Generic(if i want information sales along with finance information in a data source then generally we dont get standard one hence we can go for generic DS)
Check the below link for More about generic DS .
http://wiki.sdn.sap.com/wiki/display/BI/Generic+Extraction
for Delta capturing you can use
Timestamp(if the table has time stamp filed  so it can stamp the last changed record in that table hence it is easy to get delta based on the time stamp)
Calday- (If the table doesn't have the Timestamp filed then search for Calday where you can stamp the delta based on the date when documents are changed )
Numericpointer : If the table doesn't above both then we go for this option where you can the numeric value change stamp )
3. I read somewhere that Generic Data Source does not have Setup Table. I thought that you have to have Setup Table in order to load transaction Data otherwise you will lock the Application Tables. Where am I going wrong im my thinking please?
Generic datasource nothing but we extracting data directly from the database table without any interface between the application/systems
4. What are steps in terms of IP before, under and after Delta Initialization. I belive that you can do two ways:
Full Update - Initialize Delta Process (without Data Transfer) u2013 Delta Update or
Initialize Delta Process (with Data Transfer) u2013 Delta Update
Am I right? What is most common method and why?
Correct
5. If you want to add a filed in Data Source after 6 month using it, you want to do it without re-init Delta Queue. You add field in RSA6, then provide info for ABAP to populate new filed (info u2013 name of Data Source, Extract Structure, field added, name of Application Table which contains the field). How does it work now as there is no SetUp table it has been deleted after Initialisation? How does Delta Queue know that it is going to receive data which has been expanded by one field or it may does not need to know at all?
Once you add the new field to structure(DS) you will get the data as on date onwards not historical data hence what is the concept of setup table  ( delta records come from the Delta Que not from the setup table )
If you want histaric data to new field then you need to setp table deletion ...etc...
Hope it is clear..
Regards,
Satya