SAP BW BI Interview Pattern - RealTime approach

By:

Chandiraban singu

sdn.sap.com

Interviewers and the question will not remain the same, but find the pattern.

Brief of your profile
Brief of what you done in the project
Your challenging and complex situations
Your regularly faced problem and what you did to avoid the same in permanent
interviewers complex situation , recent situation will be posted for your analysis.

Some one may add
Your system landscape
System archiectecture
Release management
Team size, org str,....

If your exp has production support tthen generally about your roles, authorization and commonlly faced errors.
http://www.sdn.sap.com/irj/scn/index?rid=/library/uuid/b0c1d94f-b825-2c10-15ae-ccfc59acb291

About data source enhancement
http://www.sdn.sap.com/irj/scn/index?rid=/library/uuid/00c1f726-1dc2-2c10-f891-ddfbffdb1a46

About data flow during delta
http://www.sdn.sap.com/irj/scn/index?rid=/library/uuid/f03da665-bb6f-2c10-7da7-9e8a6684f2f9


If your exp has implementation.then
Modules which you have implemented.
Methodoloyg adopted
https://weblogs.sdn.sap.com/pub/wlg/13745
Approach to implementation
http://www.sdn.sap.com/irj/scn/weblogs?blog=/pub/wlg/8917
http://www.sdn.sap.com/irj/scn/weblogs?blog=/pub/wlg/8920
Testing system
Business scenario
how did you did data modellling like why std lo datasource? why dso ? why this much layers ?.....
Documentation, how your functionall spec and technical spec template, content, information will be...?

Design a SAP NetWeaver - Based System Landscape
https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/50a9952d-15cc-2a10-84a9-fd9184f35366
https://www.sdn.sap.com/irj/sdn/weblogs?blog=/pub/wlg/8877

BI - Soft yet Hard Challenges
https://www.sdn.sap.com/irj/sdn/weblogs?blog=/pub/wlg/9068

*Best Practice for new BI project *
https://www.sdn.sap.com/irj/sdn/thread?threadID=775458&tstart=0

Guidelines to Make Your BI Implementations Easier
http://www.affine.co.uk/files/Guidelines%20to%20Make%20Your%20BI%20Implementations%20Easier.pdf


Specific bw interview questions

https://www.sdn.sap.com/irj/scn/advancedsearch?query=SAP+BW+INTERVIEW+QUESTIONS&cat=sdn_all
200 BW Questions and Answers for INTERVIEWS
http://sapdocs.info/sap-overview/sap-interview-questions/
http://www.erpmastering.com/bwfaq.htm
http://www.allinterview.com/showanswers/33349.html
http://searchsap.techtarget.com/generic/0,295582,sid21_gci1182832,00.html
http://prasheelk.blogspot.com/2008_05_12_archive.html

Best of luck for your interviews.....Be clear with what you done...
http://saptutions.com/SAPBW/BW_openhub.asp
http://www.scribd.com/doc/6343052/BW-EXAM


 

SAP BI Interview Questions Cont2....

What is table partition?
A: SAP is using fact table partitioning to improve the performance. you can partition only on 0CALMONTH or 0FISCPER
How would you convert a info package group into a process chain?
A: Double Click on the info package grp, click on the ‘Process Chain Maint’ button and type in the name and descrition ; the individual info packages are inserted automatically.
How do you replace a query result from a master query to a child query?
A: If you select characterstic value with replacement path then it used the results from previuos query; for ex: let us assume that u have query Q1 which displaysthe top 10 customers, we have query Q2 which gets the top 10 customers for info object 0customer with as a vairable with replacement path and display detailed report on the customers list passed from Q1.
What is modeling?
It is an art of designing the data base. The design of DB depends on the schema and the schema is defined as representation of tables and their relationships.
What is an info cube?
Info cube is structured as star schema (extended) where a fact table is surrounded by different dim table that are linked with DIM’ids. And the data wise, you will have aggregated data in the cubes.
What is extended star schema?
In Extended Star Schema, under the BW star schema model, the dimension table does not contain master data. But it is stored externally in the master data tables (texts, attributes, hierarchies).
The characteristic in the dimensional table points to the relevant master data by the use of SID table. The SID table points to characteristics attribute texts and hierarchies.
This multistep navigational task adds extra overhead when executing a query. However the benefit of this model is that all fact tables (info cubes) share common master data tables between several info cubes.
Moreover the SID table concept allows users to implement multi languages and multi hierarchy OLAP environments. And also it supports slowly changing dimension.
delete a BEx query that is in Production system through request.
A) Using the RSZDELETE transaction
How would you optimize the dimensions?
• We should define as many dimensions as possible and we have to take care that no single dimension crosses more than 20% of the fact table size.
What are Conversion Routines for units and currencies in the update rule?
• Using this option we can write ABAP code for Units / Currencies conversion. If we enable this flag then unit of Key Figure appears in the ABAP code as an additional parameter. For example, we can convert units in Pounds to Kilos.
Can an InfoObject be an InfoProvider, how and why?
• Yes, when we want to report on Characteristics or Master Data. We have to right click on the InfoArea and select “Insert characteristic as data target”. For example, we can make 0CUSTOMER as an InfoProvider and report on it.
What is Open Hub Service?
• The Open Hub Service enables us to distribute data from an SAP BW system into external Data Marts, analytical applications, and other applications. We can ensure controlled distribution using several systems. The central object for exporting data is the InfoSpoke. We can define the source and the target object for the data. BW becomes a hub of an enterprise data warehouse. The distribution of data becomes clear through central monitoring from the distribution status in the BW system.
How do you transform Open Hub Data?
• Using BADI we can transform Open Hub Data according to the destination requirement.
What is ODS?
• Operational DataSource is used for detailed storage of data. We can overwrite data in the ODS. The data is stored in transparent tables.
What are BW Statistics and what is its use?
• They are group of Business Content InfoCubes which are used to measure performance for Query and Load Monitoring. It also shows the usage of aggregates, OLAP and Warehouse management.
What are the steps to extract data from R/3?
• Replicate DataSources
• Assign InfoSources
• Maintain Communication Structure and Transfer rules
• Create and InfoPackage
• Load Data
What are the delta options available when you load from flat file?
• The 3 options for Delta Management with Flat Files:
o Full Upload
o New Status for Changed records (ODS Object only)
o Additive Delta (ODS Object & InfoCube)
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
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
How to create a connection with LIS InfoStructures?
• LBW0 Connecting LIS InfoStructures to BW
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.
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.
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.
What is Star Schema?
In Star Schema model, Fact table is surrounded by dimensional tables. Fact table is usually very large, that means it contains millions to billions of records. On the other hand dimensional tables are very small. Hence they contain a few thousands to few million records. In practice, Fact table holds transactional data and dimensional table holds master data.
The dimensional tables are specific to a fact table. This means that dimensional tables are not shared to across other fact tables. When other fact table such as a product needs the same product dimension data another dimension table that is specific to a new fact table is needed.
This situation creates data management problems such as master data redundancy because the very same product is duplicated in several dimensional tables instead of sharing from one single master data table. This problem can be solved in extended star schema.
What is slowly changing dimension?
Dimensions those changes with time are called slowly changing dimension.
What is fact table?
Fact table is the collection if facts and relations that means foreign keys with the dimension. Actually fact table holds transactional data.
What is dimension table?
Dimension table is a collection of logically related descriptive attributes that means characteristics.
How many tables does info cube contain?
Actually info cube contains two tables’ E table and F (fact) table.
What is the maximum no. of dimensions in info cube?
16(3 are sap defines and 13 are customer defined)
What are the minimum no of dimensions in info cube?
4(3 Sap defined and 1 customer defined).
What are the 3SAP defined dimensions?
The 3 SAP defined dimensions are…..
1. Data packet dimension (P)…..it contains 3characteristics.a) request Id (b) Record type (c) Change run id
2. Time dimension (T)….it contains time characteristics such as 0calmonth, 0calday etc
3. Unit Dimension (U)…it contains basically amount and quantity related units.
What is the maximum no. of key figures?
233
What is the maximum no. of characteristics?
248
What is the model of the info cube?
Info cube model is extended star schema.
What are the data types for the characteristic info object?
There are 4types:
1. CHAR
2. NUMC
3. DATS
4. TIMS
How you’ll write date in BW?
YYYYMMDD

SAP BW BI Interview Questions Continued....

By: leela naveen

This are questions I faced. If u have any screen shots for any one of the question provide that one also.
1. We have standard info objects given in sap why you created zinfo objects can u tell me the business scenario
2. We have standard info cubes given in sap why you created zinfo cubes can u tell me the business scenario
3. In keyfigure what is meant by cumulative value, non cumulative value change and non cumulative value in and out flow.
4. when u creating infoobject it shows reference and template what is it
5. what is meant by compounding attribute tell me the scenario?
6. I have 3 cubes for that I created multiprovider and I created a report for that but I didn’t get data in that report what happen?
7. I have 10 cubes I created multiprovider I want only 1 cube data what u do?
8. what is meant by safety upper limit and safety lower limit in all the deltas tell me one by one for time stamp, calender day and numberic pointer?
9. I have 80 queries which query is taking so much time how can you solve it
10. In compression level all requests are becoming zero which data is compressing tell me detail
11. what is meant by flat aggregate?explain in detail
12. I created process chain 1st day it taking 10 min after that 1st week it taking 1 hour after that next time it taking 1 day with a same loads what happen how can u reduce the time of loading
13. how can u know the cube size? in detail show me u have screen shots
14. where can we find transport return codes
15. I have a report it taking so much time how can I rectify
16. what is offset? Without offset we create queries?
17. I told my process chains nearly 600 are there he asked me how can u monitor I told him I will see in rspcm and bwccms he asked is there any third party tools is there to see? Any tools are there to see tell me what it is
18. how client access the reports
19. I don’t have master data it will possible to load transaction data? it is possible is there any other steps to do that one
20. what is structure in reporting?
21. which object based you created extended star schema?
22. what is line item dimension tell me brief
23. what is high cardinality tell me brief
24. process chain is running I have to stop the process for 1 hour after that re runn the process where it is stopped?
in multiprovider can I use aggregations
25. what is direct schedule and what is meta chain
26. which patch u used presently? How can I know which patch that one?
27. how can we increase data packet size
28. hierarchies are not there in bi?why
29. remodeling is applied only on info cube? why not dso/ods?
30. In jump queries we can jump any transactions just like rsa1, sm37 etc it is possible or not?
31. why ods activation fail? What types of fails are there? What are the steps to handle
32. I have a process chain is running the infopackage get error don’t process the error of that info package and then you can run the dependent variants is it possible?

Give me any performance and loading issues or support issues
Reporting errors, Loading errors, process chain errors?