EXTRACTION INTERVIEW QUESTIONS IN SAP BW

Q1:  WHAT ARE THE STEPS INVOLVED IN LO EXTRACTION?

Ans:
Go to Transaction LBWE (LO Customizing Cockpit)
1). Select Logistics Application
      e.g. SD Sales BW
            Extract Structures
2). Select the desired Extract Structure and deactivate it first.
3). Give the Transport Request number and continue
4). Click on `Maintenance' to maintain such Extract Structure
       Select the fields of your choice and continue
             Maintain DataSource if needed
5). Activate the extract structure
6). Give the Transport Request number and continue
Next step is to delete the setup tables
7). Go to T-Code SBIW
8). Select Business Information Warehouse
i. Setting for Application-Specific Datasources
ii. Logistics
iii. Managing Extract Structures
iv. Initialization
v. Delete the content of Setup tables (T-Code LBWG)
vi. Select the application (01 – Sales & Distribution) and Execute
Now, Fill the Setup tables
9). Select Business Information Warehouse
i. Setting for Application-Specific Datasources
ii. Logistics
iii. Managing Extract Structures
iv. Initialization
v. Filling the Setup tables
vi. Application-Specific Setup of statistical data
vii. SD Sales Orders – Perform Setup (T-Code OLI7BW)
        Specify a Run Name and time and Date (put future date)
             Execute
Check the data in Setup tables at RSA3
Replicate the DataSource
Use of setup tables:
You should fill the setup table in the R/3 system and extract the data to BW - the setup tables is in SBIW - after that you can do delta extractions by initialize the extractor.
Full loads are always taken from the setup tables

Q2: HOW DELTA WORKS FOR LO EXTRACTION AND WHAT ARE UPDATE METHODS?           

Ans:
Type 1: Direct Delta

• Each document posting is directly transferred into the BW delta queue
• Each document posting with delta extraction leads to exactly one LUW in the respective BW delta queues

Type 2: Queued Delta

• Extraction data is collected for the affected application in an extraction queue
• Collective run as usual for transferring data into the BW delta queue

Type 3: Un-serialized V3 Update

• Extraction data for written as before into the update tables with a V3 update module
•  V3 collective run transfers the data to BW Delta queue
• In contrast to serialized V3, the data in the updating collective run is without regard to sequence from the update tables

Q3: HOW TO CREATE GENERIC EXTRACTOR?

Ans:
1.      Select the DataSource type and give it a technical name.
2.      Choose Create.
The creating a generic DataSource screen appears.
3.      Choose an application component to which the DataSource is to be assigned.
4.      Enter the descriptive texts. You can choose any text.
5.      Choose from which datasets the generic DataSource is to be filled.

• Choose Extraction from View, if you want to extract data from a transparent table or a database view. Choose Extraction from Query, if you want to use a SAP query InfoSet as the data source. Select the required InfoSet from the InfoSet catalog.
• Choose Extraction using FM, if you want to extract data using a function module. Enter the function module and extract structure.
• With texts, you also have the option of extraction from domain fixed values.

6.      Maintain the settings for delta transfer where appropriate.
7.      Choose Save.
When extracting, look at SAP Query: Assigning to a User Group.
Note when extracting from a transparent table or view:
If the extract structure contains a key figure field, that references to a unit of measure or currency unit field, this unit field must appear in the same extract structure as the key figure field.
A screen appears in which you can edit the fields of the extract structure.
8. Choose DataSource ® Generate.
The DataSource is now saved in the source system.

Q4: HOW TO ENHANCE A DATASOURCE?    

Ans:
Step 1: Go to T Code CMOD and choose the project you are working on.
Step 2: Choose the exit which is called when the data is extracted.
Step 3: There are two options
Normal Approach: CMOD Code
Function Module Approach: CMOD Code
Step 4: Here in this step we create a function module for each data source. We create a new FM
(Function Module in SE37)
Data Extractor Enhancement - Best Practice/Benefits:
This is the best practice of data source enhancement. This has the following benefits:

• No more locking of CMOD code by 1 developer stopping others to enhance other extractors.
• Testing of an extractor becomes more independent than others.
• Faster and a more robust Approach

Q5: WHAT ARE VARIOUS WAYS TO MAKE GENERIC EXTRACTOR DELTA ENABLED?  

Ans:
This field from the extraction structure of a DataSource meets one of the following criteria:
1. The field has the following type: Time stamp. New records to be loaded into the BW using a delta upload have a higher entry in this field than the time stamp of the last extraction.
2. The field has the following type: Calendar day. The same criterion applies to new records as in the time stamp field.
3. The field has another type. This case is only supported for SAP Content DataSources. In this case, the maximum value to be read must be displayed using a DataSource-specific exit when beginning data extraction.

Q6: WHAT ARE SAFETY INTERVALS?

Ans
This field is used by DataSources that determine their delta generically using a repetitively-increasing field in the extract structure.
The field contains the discrepancy between the current maximum when the delta or delta init extraction took place and the data that has actually been read.
Leaving the value blank increases the risk that the system could not extract records arising during extraction.
Example: A time stamp is used to determine the delta. The time stamp that was last read is 12:00:00. The next delta extraction begins at 12:30:00. In this case, the selection interval is 12:00:00 to 12:30:00. At the end of extraction, the pointer is set to 12:30:00.
A record - for example, a document- is created at 12:25 but not saved until 12:35. It is not contained in the extracted data but, because of its time stamp, is not extracted the next time either.

Q7: HOW IS COPA DATASOURCE SET UP?

Ans:
R/3 System
1. Run KEB0
2. Select Datasource 1_CO_PA_CCA
3. Select Field Name for Partitioning (Eg, Ccode)
4. Initialize
5. Select characteristics & Value Fields & Key Figures
6. Select Development Class/Local Object
7. Workbench Request
8. Edit your Data Source to Select/Hide Fields
9. Extract Checker at RSA3 & Extract
BW System
1. Replicate Data Source
2. Assign Info Source
3. Transfer all Data Source elements to Info Source
4. Activate Info Source
5. Create Cube on Infoprovider (Copy str from Infosource)
6. Go to Dimensions and create dimensions, Define & Assign
7. Check & Activate
8. Create Update Rules
9. Insert/Modify KF and write routines (const, formula, abap)
10. Activate
11. Create InfoPackage for Initialization
12. Maintain Infopackage
13. Under Update Tab Select Initialize delta on Infopackage
14. Schedule/Monitor
15. Create Another InfoPackage for Delta
16. Check on DELTA Option
17. Ready for Delta Load

Q8: WHAT ARE VARIOUS WAYS TO TRACK DELTA RECORDS?

Ans:
RSA7, LBWQ, Idocs and SMQ1.