SAP BW Interview

 SAP BW Interview Questions
1. What are the extractor types?
• Application Specific
o BW Content FI, HR, CO, SAP CRM, LO Cockpit
o Customer-Generated Extractors
LIS, FI-SL, CO-PA
• Cross Application (Generic Extractors)
o DB View, InfoSet, Function Module

2. What are the steps involved in LO Extraction?
• The steps are:
o RSA5 Select the DataSources
o LBWE Maintain DataSources and Activate Extract Structures
o LBWG Delete Setup Tables
o 0LI*BW Setup tables
o RSA3 Check extraction and the data in Setup tables
o LBWQ Check the extraction queue
o LBWF Log for LO Extract Structures
o RSA7 BW Delta Queue Monitor

3. How to create a connection with LIS InfoStructures?
• LBW0 Connecting LIS InfoStructures to BW

4. What is the difference between ODS and InfoCube and MultiProvider?
• ODS: Provides granular data, allows overwrite and data is in transparent tables, ideal for drilldown and RRI.
• CUBE: Follows the star schema, we can only append data, ideal for primary reporting.
• MultiProvider: Does not have physical data. It allows to access data from different InfoProviders (Cube, ODS, InfoObject). It is also preferred for reporting.

5. What are Start routines, Transfer routines and Update routines?
• Start Routines: The start routine is run for each DataPackage after the data has been written to the PSA and before the transfer rules have been executed. It allows complex computations for a key figure or a characteristic. It has no return value. Its purpose is to execute preliminary calculations and to store them in global DataStructures. This structure or table can be accessed in the other routines. The entire DataPackage in the transfer structure format is used as a parameter for the routine.
• Transfer / Update Routines: They are defined at the InfoObject level. It is like the Start Routine. It is independent of the DataSource. We can use this to define Global Data and Global Checks.

6. What is the difference between start routine and update routine, when, how and why are they called?
• Start routine can be used to access InfoPackage while update routines are used while updating the Data Targets.

7. What is the table that is used in start routines?
• Always the table structure will be the structure of an ODS or InfoCube. For example if it is an ODS then active table structure will be the table.

8. Explain how you used Start routines in your project?
• Start routines are used for mass processing of records. In start routine all the records of DataPackage is available for processing. So we can process all these records together in start routine. In one of scenario, we wanted to apply size % to the forecast data. For example if material M1 is forecasted to say 100 in May. Then after applying size %(Small 20%, Medium 40%, Large 20%, Extra Large 20%), we wanted to have 4 records against one single record that is coming in the info package. This is achieved in start routine.

9. What are Return Tables?
• When we want to return multiple records, instead of single value, we use the return table in the Update Routine. Example: If we have total telephone expense for a CostCenter, using a return table we can get expense per employee.

10. How do start routine and return table synchronize with each other?
• Return table is used to return the Value following the execution of start routine