SAP BI INTERVIEW QUESTIONS

SAP BW Tricks and Tips!
Everyday handy list of BW tricks and useful tips. If you have any of your own, please feel free to share….
• Table TSTC contains all the t-codes availabe in the system. This even contains the custom (zxxxxx) created ones
• To find who has changed an object recently; Tab E071 gives the CRs that changed the object, input this CR info in Tab E070 to find the user name
• T-code SE39 can be used to compare programs or update rules across different sytems. This is very useful to match the code between developement and production systems
• T-code SM21 can be useful in finding additional information on failures in a system along with ShortDumps(t-code ST22)
• Easiest way to get the table name of PSA; go to Tab RSTSODSPART and input the Request number from the load monitor. Field ODSNAME_TECH gives the PSA.

SAP BW Interview Questions!
• Differences between an ODS/DSO and an InfoCube
• Differences between TransferRules and UpdateRules
• What is the role of StartRoutine in TransferRules and UpdateRules
• Performance improvement in loading and reporting
• Difference between RollUp and Compression
• What is the role of ChangeRun
• What is a ShortDump
• What is the use of NumberRange Buffering
• Use of LineItem Dimension and HighCardinality check options in a InfoCube
• Use and limitations on Partitioning of an InfoCube.


• How to access ABAP-Editor(program) without using SE38 t-code
• These steps explain how to access an SE38 ABAP program without using the t-code SE38 Go any of the update rules.   Click on Display activated program Click on others Click on program, enter the program name and continue. Now you will be in the program you wanted to access.
 
• Transactional InfoCubes (T-Cubes)

Transactional InfoCubes are used in connection with the entry of planning data. The data from T-Cube is accessed Transactionally, i.e. Data is written to the InfoCube (possibly by several users at the same time). While Standard InfoCubes are used for Read-Only access. Transactional InfoCubes can be filled with data using two different methods: Loading planned data via BW-BPS or via BW Staging, where no planned data can be loaded. Creating a Transactional InfoCube: STEP1: GoTo T-Code RSA1, Creat an InfoArea and then Rt.Click on InfoArea and select Create InfoCube as shown STEP2: Then it popup the new screen, Give name of InfoCube and Description , then Select the Check box Real Time and then Press Create as shown STEP3: Now assign the Characteristics to the Created dimensions & Key Figures to the keyfigs folder same as we normally do for the cube and Activate. This is how we Create a Transaction Cubes, Now we will.

SAP BW Production Support Issues
As we know, the production SAP BW daily batch comprises of extracting data from the source systems like SAP R/3 and other database systems and then loading into corresponding data targets in SAP BW.
Here is the list of of common SAP BW prodcution support issues we encounter in daily BW batch.
• Long running BW loads and ultimately leading to max. run time failures
• BW loads failing due to lock issues on the objects
• Load failures due to duplicate data being extracted from source system
• Load failures due to Number range buffering / SID generation errors
• ODS activation failures
• Fill aggregates / info cube compression step failures
• Load failures due to invalid chars in the data
• Connection issues between SAP systems and IDOC processing failures
• Occasional data source replication issues
Sap landscape:
Landscape is like a server system or like a layout of the servers or some may even call it the architecture of the servers viz. SAP is divided into three different lanscape DEV, QAS and PROD.
-  DEV would have multiple clients for ex: 190- Sandbox, 100- Golden, 180- Unit Test.
-  QAS may again have mutiple clients for ex: 300- Integration Test, 700 to 710 Training.
-  PROD may have something like a 200 Production.

These names and numbers are the implementer's discreet on how they want it or they have been using in their previous implementations or how is the client's business scenario.
Now whatever you do in the Sandbox doesn't affect the other servers or clients. Whenever you think you are satisfied with your configuration and you think you can use it moving forward, you RE-DO it in the golden client (remember, this is a very neat and clean client and you cannot use it for rough usage). As you re-do everything that you had thought was important and usable, you get a transport request pop up upon saving everytime. You save it under a transport request and give your description to it. Thus the configuration is transported to the Unit Test client (180 in this example).
You don't run any transaction or even use the SAP Easy Access screen on the 100 (golden) client. This is a configuration only client. Now upon a successful tranport by the Basis guy, you have all the configuration in the Testing client, just as it is in the Golden client. The configuration remains in sync between these two clients.
But in the Testing client you can not even access SPRO  (Display IMG) screen. It's a transaction only client where you perform the unit test. Upon a satisfactory unit test, you move the good configuration to the next SERVER (DEV). The incorrect or unsatisfactory configuration is corrected in Golden (may again as well be practised in the sandbox prior to Golden) and accordingly transported back to 180 (Unit Test) until the unit test affected by that particular config is satisfactory.
The Golden client remains the 'database' (if you wanna call it that) or you may rather call it the 'ultimate' reference client for all the good, complete and final configuration that is being used in the implementation.






BW Interview Questions questions:-

What is ODS?
It is operational data store. ODS is a BW Architectural component that appears between PSA ( Persistant Staging Area ) and infocubes and that allows Bex ( Business Explorer ) reporting. It is not based on the star schema and is used primarily for details reporting, rather than for dimensional analysis. ODS objects do not aggregate data as infocubes do. Data are loaded into an ODS object by inserting new records, updating existing records, or deleting old records as specified by RECORDMODE value.

Q. How much time does it take to extract 1 million of records from an infocube?
ans. This depends,if you have complex coding in update rules it will take longer time,orelse it will take less than 30 mins.

Q. What are the four ASAP Methodologies?
ans:
Project plan
ReQuirements gathering
Gap Analysis
Project Realization
Q. How do you measure the size of infocube?
ans: In no of records
Q. Difference between infocube and ODS?
ans:
Infocube is structured as star schema(extended) where in a fact table is surrounded by different dim table which connects to sids. And the data wise, you will have aggregated data in the cubes.
ODS is a flat structure(flat table) with no star schema concept and which will have granular data(detailed level).
Q. Difference between display attributes and navigational attributes?
ans:
Display attribute is one which is used only for display purpose in the report .Whereas navigational attribute is used for drilling down in the report. We don't need to maintain Nav attribute in the cube as a characteristic (that is the advantage) to drill down.
Q. SOME DATA IS UPLOADED TWICE INTO INFOCUBE. HOW TO CORRECT IT?
ans: But how is it possible?.If you load it manually twice, then you can delete it by request.
Q . CAN U ADD A NEW FIELD AT THE ODS LEVEL?
ans. Sure you can.ODS is nothing but a table.
Q. CAN NUMBER OF DATASOURCE HAS ONE INFOSOURCE?
ans. Yes of course. For example, for loading text and hierarchies we use different data sources but the same info source.
Q. BRIEF THE DATAFLOW IN BW.
ans. Data flows from transactional system to analytical system(BW).DS on the transactional system needs to be replicated on BW side and attached to infosource and update rules respectively.
Q. WHAT IS PROCEDURE TO UPDATE DATA INTO DATA TARGETS?
ans. Full and delta.
Q7. AS WE USE Sbwnn,SBiw1,sbiw2 for delta update in LIS THEN WHAT IS THE PROCEDURE IN LO-COCKPIT?

ans. No lis in lo cokpit. We will have data sources and can be maintained(append fields).Refer white paper on LO- Cokpit extractions.
Q8. SIGNIFICANCE OF ODS.
ans. It holds granular data.
Q9. WHERE THE PSA DATA IS STORED?
ans. In PSA table.
Q10.WHAT IS DATA SIZE?
ans. The volume of data one data target holds(in no.of records)