SAP BW Interview Questions 2
1) What is process chain? How many types are there? How many we use in real time scenario? Can we define interdependent processes with tasks like data loading, cube compression, index maintenance, master data & ods activation in the best possible performance & data integrity.
2) What is data integrityand how can we achieve this?
3) What is index maintenance and what is the purpose to use this in real time?
4) When and why use infocube compression in real time?
5) What is mean by data modelling and what will the consultant do in data modelling?
6) How can enhance business content and what for purpose we enhance business content (becausing we can activate business content)
7) What is fine-tuning and how many types are there and what for purpose we done tuning in real time. tuning can only be done for infocube partitions and creating aggregates or any other?
8) What is mean by multiprovider and what purpose we use multiprovider?
9) What is scheduled and monitored data loads and for what purpose?
Ans # 1:
Process chains exists in Admin Work Bench. Using these we can automate ETTL processes. These allows BW guys to schedule all activities and monitor (T Code: RSPC).
PROCESS CHAIN - Before defining PROCESS CHAIN, let us define PROCESS in any given process chain. Is a procedure either with in the SAP or external to it with a start and end. This process runs in the background.
PROCESS CHAIN is set of such processes that are linked together in a chain. In other words each process is dependent on the previous process and dependencies are clearly defined in the process chain.
This is normally done in order to automate a job or task that has to execute more than one process in order to complete the job or task.
1. Check the Source System for that particular PC.
2. Select the request ID (it will be in Header Tab) of PC
3. Go to SM37 of Source System.
4. Double Click on the Job.
5. You will navigate to a screen
6. In that Click "Job Details" button
7. A small Pop-up Window comes
8. In the Pop-up screen, take a note of
a) Executing Server
b) WP Number/PID
9. Open a new SM37 (/OSM37) command
10. In the Click on "Application Servers" button
11. You can see different Application Servers.
11. Goto Executing server, and Double Click (Point 8 (a))
12. Goto PID (Point 8 (b))
13. On the left most you can see a check box
14. "Check" the check Box
15. On the Menu Bar.. You can see "Process"
16. In the "process" you have the Option "Cancel with Core"
17. Click on that option. * -- Ramkumar K
Ans # 2:
Data Integrity is about eliminating duplicate entries in the database and achieve normalization.
Ans # 4:
InfoCube compression creates new cube by eliminating duplicates. Compressed infocubes require less storage space and are faster for retrieval of information. Here the catch is .. Once you compress, you can't alter the InfoCube. You are safe as long as you don't have any error in modeling.
This compression can be done through Process Chain and also manually.
Tips by: Anand
Indexing is a process where the data is stored by indexing it. Eg: A phone book... When we write somebodys number we write it as Prasads number would be in "P" and Rajesh's number would be in "R"... The phone book process is indexing.. similarly the storing of data by creating indexes is called indexing.
Datamodeling is a process where you collect the facts..the attributes associated to facts.. navigation atributes etc.. and after you collect all these you need to decide which one you ill be using. This process of collection is done by interviewing the end users, the power users, the share holders etc.. it is generally done by the Team Lead, Project Manager or sometimes a Sr. Consultant (4-5 yrs of exp) So if you are new you dont have to worry about it....But do remember that it is a imp aspect of any datawarehousing soln.. so make sure that you have read datamodeling before attending any interview or even starting to work....
We can enhance the Business Content bby adding fields to it. Since BC is delivered by SAP Inc it may not contain all the infoobjects, infocubes etc that you want to use according to your company's data model... eg: you have a customer infocube(In BC) but your company uses a attribute for say..apt number... then instead of constructing the whole infocube you can add the above field to the existing BC infocube and get going...
Tuning is the most imp process in BW..Tuning is done the increase efficiency.... that means lowering time for loading data in cube.. lowering time for accessing a query.. lowering time for doing a drill down etc.. fine tuning=lowering time(for everything possible)...tuning can be done by many things not only by partitions and aggregates there are various things you can do... for eg: compression, etc..
Multiprovider can combine various infoproviders for reporting purposes.. like you can combine 4-5 infocubes or 2-3 infocubes and 2-3 ODS or IC, ODS and Master data.. etc.. you can refer to help.sap.com for more info...
Scheduled data load means you have scheduled the loading of data for some particular date and time you can do it in scheduler tab if infoobject... and monitored means you are monitoring that particular data load or some other loads by using transaction RSMON.
1.Procedure for repeat delta?
You need to make the request status to Red in monitor screen and then delete it from ODS/Cube. Then when you open infopackage again, system will prompt you for repeat delta.
->F2->Update Mode--->Delta Repetation
Delta repeation is done based on type of upload you are carrying on.
1. if you are loading masterdata then most of the time you will change the QM status to red and then repeat the delta for the repeat of delta. the delta is allowed only if you make the changes.
and some times you need to do the RnD if the repeat of delta is not allowed even after the qm status id made to red. here you have to change the QM status to red.
If this is not the case, the source system and therefore also the extractor, have not yet received any information regarding the last delta and you must set the request to GREEN in the monitor using a QM action.
The system then requests a delta again since the last delta request has not yet occurred for the extractor.
Afterwards, you must reset the old request that you previously set to GREEN to RED since it was incorrect and it would otherwise be requested as a data target by an ODS.
Caution: If the termianted request was a REPEAT request itself, always set this to RED so that the system tries to carry out a repeat again.
To determine whether a delta or a repeat are to be requested, the system ONLY uses the status of the monitor.
It is irrelevant whether the request is updated in a data target somewhere.
When activating requests in an ODS, the system checks delta repeat requests for completeness and the correct sequence.
Each green delta/repeat request in the monitor that came from the same DataSource/source system combination must be updated in the ODS before activation, which means that in this case, you must set them back to RED in the monitor using a QM action when using the solution described above.
If the source of the data is a DataMart, it is not just the DELTARNR field that is relevant (in the roosprmsc table in the system in which the source DataMart is, which is usually your BW system since it is a Myself extraction in this case), rather the status of the request tabstrip control is relevant as well.
Therefore, after the last delta request has terminated, go to the administration of your data source and check whether the DataMart indicator is set for the request that you wanted to update last.
If this is NOT the case, you must NOT request a repeat since the system would also retransfer the data of the last delta but one.
This means, you must NOT start a delta InfoPackage which then would request a repeat because the monitor is still RED. For information about how to correct this problem, refer to the following section.
For more information about this, see also Note 873401.
Proceed as follows:
Delete the rest of this request from ALL updated data targets, set the terminated request to GREEN IN THE MONITOR and request a new DELTA.
Only if the DataMart indicator is set does the system carry out a repeat correctly and transfers only this data again.
This means, that only in this case can you leave the monitor status as it is and restart the delta InfoPackage. Then this creates a repeat request
In addition, you can generally also reset the DATAMART indicator and then work using a delta request after you have set the incorrect request to GREEN in the monitor.
Simply start the delta InfoPackage after you have reset the DATAMART indicator AND after you have set the last request that was terminated to GREEN in the monitor.
After the delta request has been carried out successfully, remember to reset the old incorrect request to RED since otherwise the problems mentioned above will occur when you activate the data in a target ODS.
What is process chain and how you used it?
A) Process chains are tool available in BW for Automation of upload of master data and transaction data while taking care of dependency between each processes.
B) In one of our scenario we wanted to upload wholesale price infoobject which will have wholesale price for all the material. Then we wanted to load transaction data. While loading transaction data to populate wholesale price, there was a look up in the update rule on this InfoObject masterdata table. This dependency of first uploading masterdata and then uploading transaction data was done through the process chain.
What is process chain and how you used it?
A) We have used process chains to automate the delta loading process. Once you are finished with your design and testing you can automate the processes listed in RSPC. I have a real time example in the attachment.
for more detail
/thread/235805 [original link is broken]
Message was edited by:
<b>1. What is process chain and how you used it?</b>
Process chains are tool available in BW for Automation of upload of master data and transaction data while taking care of dependency between each processes.
<b>2. What is transaction for creating Process Chains ?</b>
<b> 3. Explain Colector Process ?</b>
Collector processes are used to manage multiple predecessor
processes that feed into the same subsequent process. The collector
processes available for BW are:
All of the direct predecessor processes must raise an event in order for subsequent processes to be executed
A least one predecessor process must send an event The first predecessor process that sends an event triggers the subsequent process
Any additional predecessor processes that send an event will again trigger
subsequent process (Only if the chain is planned as periodic)
EXOR : Exclusive OR
Similar to regular OR, but there is only ONE execution of the successor
processes, even if several predecessor processes raise an event
<b>4. What are application Process ?</b>
Application processes represent BW activities that are typically
performed as part of BW operations.
Attribute/Hierarchy Change run
Reporting Agent Settings
<b>5. Tell some facts about process Chains</b>
Process chains are transportable Button for writing to a change request when
maintaining a process chain in RSPC
Process chains available in the transport connection wizard (administrator workbench)
If a process dumps, it is treated in the same manner as a failed process
Graphical display of Process Chain Maintenance requires the 620 SAPGUI and SAP BW 3.0B Frontend GUI
A special control background job runs to facilitate the execution of the of the other batch jobs of the process chain
Note your BTC process distribution, and make sure that an extra BTC process is available so the supporting control job can run immediately
<b>6. What happens when chain is activated ?</b>
When a chain gets activated It will be copied into active version The processes will be planned in batch as program RSPROCESS with type and variant given as parameters with job name BI_PROCESS_<TYPE> waiting for event, except the trigger The trigger is planned as specified in its variant, if start via meta-chain it is not planned to batch
<b>7. Steps in process chains ?</b>
Go to transaction code-> RSPC
Follow the Basic Flow of Process chain..
1. Start chain
2. Delete BasicCube indexes
3. Load data from the source system into the PSA
4. Load data from the PSA into the ODS object
5. Activate data in the ODS object
6. Load data from the ODS object in the BasicCube
7. Create indexes after loading for the BasicCube
Hope the following links will give u a clear idea about process chains and clear ur doubts.
Siggi's weblogs for data load error and how to restart process chain
****Assign Points If Helpful****
Check these questions?
1. What are the extractor types?
u2022 Application Specific
o BW Content FI, HR, CO, SAP CRM, LO Cockpit
o Customer-Generated Extractors
LIS, FI-SL, CO-PA
u2022 Cross Application (Generic Extractors)
o DB View, InfoSet, Function Module
2. What are the steps involved in LO Extraction?
u2022 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?
u2022 LBW0 Connecting LIS InfoStructures to BW
4. What is the difference between ODS and InfoCube and MultiProvider?
u2022 ODS: Provides granular data, allows overwrite and data is
in transparent tables, ideal for drilldown and RRI.
u2022 CUBE: Follows the star schema, we can only append data,
ideal for primary reporting.
u2022 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?
u2022 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.
u2022 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.