1) Please describe your experience with BEx (Business Explorer)
A) Rate your level of experience with BEx and the rationale for you’re self-rating
B) How many queries have you developed? :
C) How many reports have you written?
D) How many workbooks have you developed?
E) Experience with jump targets (OLTP, use jump target)
F) Describe experience with BW-compatible ETL tools (e.g. Ascential)
2) What is SAP BW/BI? What is the purpose of SAP BW/BI?
SAP BW/BI stands for Business Information Warehouse, also known as business intelligence. For any business, data reporting, analyses and interpretation of business data is very crucial for running business smoothly and making decision. SAP BW/BI manage the data and enables to react quickly and in line with the market. It enables the user to analyze data from operative SAP applications as well as from other business.
3) Describe your experience with the design and implementation of standard & custom InfoCubes.
1. How many InfoCubes have you implemented from start to end by yourself (not with a team)?
2. Of these Cubes, how many characteristics (including attributes) did the largest one have.
3. How much customization was done on the InfoCubes have you implemented?
4) What is data Integrity?
Data integrity is to eliminate duplicate entries in the database.
5) What is table partition?
Table partition is done to manage the huge data to improve the efficiency of the applications. The partition is based on 0CALMONTH and 0FISCPER. There are two type of partitioning that is done
a) Database partitioning
b) Logical partitioning
6) What is data flow in BW/BI?
Data flows from a transactional system to the analytical system (BW). DS ( Data Service) on the transactional system needs to be replicated on BW side and attached to infosource and update rules respectively.
7) Describe your experience with BW extractors
1. How many standard BW extractors have you implemented?
2. How many custom BW extractors have you implemented?
8) Describe how you have used Excel as a compliment to BEx
A) Describe your level of expertise and the rationale for your self-rating (experience with macros, pivot tables and formatting)B)
9) What is ODS (Operational Data Store)?
‘Operational Data Store’ or ‘ODS’ is used for detailed storage of data. It is a BW architectural component that appears between PSA ( Persistent Staging Area) and infocubes, it allows BEX (Business Explorer) reporting. It is primarily used for detail reporting rather than dimensional analysis, and it is not based on the star schema. ODS (Operational Data Store) objects do not aggregate data as infocubes do. To load the data into an IDS object, new records are inserted, existing records are updated, or old records are deleted as specified by RECORDMODE value.
10) What is the difference between ODS and Info-cubes?
The difference between ODS and Info-cubes are
a) ODS has a key while Info-cubes does not have any key
b) ODS contains detailed level data while Info-cube contains refined data
c) Info-cube follows Star Schema (16 dimensions) while ODS is a flat file structure
d) There can be two or more ODS under a cube, so cube can contain combined data or data that is derived from other fields in the ODS
11) What is the dimension in BW? How would you optimize the dimensions?
A dimension in BW is a collection of reference information about a measurable event in data warehousing. In this context, events are known as “facts”. For example, a customer dimension’s attributes could include first and last name, gender, birth date etc. To optimize the dimensions, do not add most dynamic characteristics into the same dimension and make the dimension smaller. Also, define as many dimensions as possible, and the dimension should not exceed 20% of the fact table size.
12) What is partitioning and what are the benefits of partitioning in an InfoCube?
A) Partitioning is the method of dividing a table (either column wise or row wise) based on the fields available which would enable a quick reference for the intended values of the fields in the table. By partitioning an infocube, the reporting performance is enhanced because it is easier to search in smaller tables. Also table maintenance becomes easier.
13) What does Rollup do?
A) Rollup creates aggregates in an infocube whenever new data is loaded.
14) What are the inputs for an infoset?
A) The inputs for an infoset are ODS objects and InfoObjects (with master data or text).
15) What internally happens when BW objects like Info Object, Info Cube or ODS are created and activated?
A) When an InfoObject, InfoCube or ODS object is created, BW maintains a saved version of that object but does not make it available for use. Once the object is activated, BW creates an active version that is available for use.
16) What is the maximum number of key fields that you can have in an ODS object?
17) What is the specific advantage of LO extraction over LIS extraction?
A) The load performance of LO extraction is better than that of LIS. In LIS two tables are used for delta management that is cumbersome. In LO only one delta queue is used for delta management.
18) What is the importance of 0REQUID?
A) It is the InfoObject for Request id. OREQUID enables BW to distinguish between different data records.
19) Can you add programs in the scheduler?
A) Yes. Through event handling.
20) What is the importance of the table ROIDOCPRMS?
A) It is an IDOC parameter source system. This table contains the details of the data transfer like the source system of the data, data packet size, maximum number of lines in a data packet, etc. The data packet size can be changed through the control parameters option on SBIW i.e., the contents of this table can be changed.
21) What is the importance of 'start routine' in update rules?
A) A Start routine is a user exit that can be executed before the update rule starts to allow more complex computations for a key figure or a characteristic. The start routine has no return value. Its purpose is to execute preliminary calculations and to store them in a global data structure. You can access this structure or table in the other routines.
22) When is IDOC data transfer used?
A) IDOCs are used for communication between logical systems like SAP R/3, R/2 and non-SAP systems using ALE and for communication between an SAP R/3 system and a non-SAP system. In BW, an IDOC is a data container for data exchange between SAP systems or between SAP systems and external systems based on an EDI interface. IDOCs support limited file size of 1000 bytes. So IDOCs are not used when loading data into PSA since data there is more detailed. It is used when the file size is lesser than 1000 bytes.
23) What is partitioning characteristic in CO-PA used for?
A) For easier parallel search and load of data.
24) What is the advantage of BW reporting on CO-PA data compared with directly running the queries on CO-PA?
A) BW has a better performance advantage over reporting in R/3. For a huge amount of data, the R/3 reporting tool is at a serious disadvantage because R/3 is modeled as an OLTP system and is good for transaction processing rather than analytical processing.
25) What is the function of BW statistics cube?
A) BW statistics cube contains the data related to the reporting performance and the data loads of all the InfoCubes in the BW system.
26) When an ODS is in 'overwrite' mode, does uploading the same data again and again create new entries in the change log each time data is uploaded?
27) What is the function of 'selective deletion' tab in the manage->contents of an infocube?
A) It allows us to select a particular value of a particular field and delete its contents.
28) When we collapse an infocube, is the consolidated data stored in the same infocube or is it stored in the new infocube?
A) Data is stored in the same cube.
29) What is the effect of aggregation on the performance? Are there any negative effects on the performance?
A) Aggregation improves the performance in reporting.
30) What happens when you load transaction data without loading master data?
A) The transaction data gets loaded and the master data fields remain blank.
31) When given a choice between a single infocube and multiple InfoCubes with a multiprovider, what factors does one need to consider before making a decision?
A) One would have to see if the InfoCubes are used individually. If these cubes are often used individually, then it is better to go for a multiprovider with many cubes since the reporting would be faster for an individual cube query rather than for a big cube with lot of data.
32) How many hierarchy levels can be created for a characteristic info object?
A) Maximum of 98 levels.
33) What is open hub service?
A) The open hub service enables you to distribute data from an SAP BW system into external data marts, analytical applications, and other applications. With this, you can ensure controlled distribution using several systems. The central object for the export of data is the Infospoke. Using this, you can define the object from which the data comes and into which target it is transferred. Through the open hub service, SAP 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.
34) What is the function of 'reconstruction' tab in an infocube?
A) It reconstructs the deleted requests from the infocube. If a request has been deleted and later someone wants the data records of that request to be added to the infocube, one can use the reconstruction tab to add those records. It goes to the PSA and brings the data to the infocube.
35) What are secondary indexes with respect to InfoCubes?
A) Index created in addition to the primary index of the infocube. When you activate a table in the ABAP Dictionary, an index is created on the primary key fields of the table. Further indexes created for the table are called secondary indexes.
36) What is DB connect and where is it used?
A) DB connect is database connecting piece of program. It is used in connecting third party tools with BW for reporting purpose.
37) Can we extract hierarchies from R/3 for CO-PA?
A) No We cannot, “NO hierarchies in CO/PA?.
38) Explain ‘field name for partitioning’ in CO-PA
A) The CO/PA partitioning is used to decrease package size (eg: company code)
39) What is V3 update method ?
A) It is a program in R/3 source system that schedules batch jobs to update extract structure to data source collectively.
40) What is modelling?
Designing of data base is done by using modelling. The design of DB (Data Base) depends on the schema, and schema is defined as the representation of tables and their relationship.
41) What is the common method of finding the tables used in any R/3 extraction
A) By using the transaction LISTSCHEMA we can navigate the tables.
42) Differences between table view and infoset query
A) An InfoSet Query is a query using flat tables.
43) How to load data from one InfoCube to another InfoCube ?
A) Thro DataMarts data can be loaded from one InfoCube to another InfoCube.
44) What is extended star schema?
Star Schema comprises of Fact tables and Dimension Tables, while the table that consists the Master data are kept in separate tables. These separate tables for Master data are referred as Extended Star Schema.
45) Difference between extract structure and datasource
A) In Datasource we define the data from diff source sys,where as in extract struct it contains the replicated data of datasource n where in we can define extract rules, n transfer rulesB) Extract Structure is a record layout of InfoObjects.C) Extract Structure is created on SAP BW system.
46) What are the data types for the characteristics info object?
There are 4 types
47) What is referential integrity mechanism ?
A) Referential integrity is the property that guarantees that values from one column depend on values from another column.This property is enforced through integrity constraints.
48) Do you have any idea how to improve the performance of the BW..?
Asynchronous Updating (V2 Update)
With this update type, the document update is made separately from the statistics update. A termination of the statistics update has NO influence on the document update (see V1 Update).
Radio button: Updating in U3 update program
Asynchronous Updating (V3 Update)
With this update type, updating is made separately from the document update. The difference between this update type and the V2 Update lies,however, with the time schedule. If the V3 update is active, then the update can be executed at a later time.
In contrast to V1 and V2 Updates, no single documents are updated. The V3 update is, therefore, also described as a collective update.
49) What are the transaction codes for process chain?
a) RSPC: Process Chain Maintenance
b) RSPC1: Process Chain Display
c) RSPCM: Monitor daily process chains
d) RZ20: To see log for process chains
50) What is B/W statistics and how it is used?
The sets of cubes delivered by SAP are used to measure performance for query, loading data etc. B/W statistics as the name suggests is useful in showing data about the costs associated with the B/W queries, OLAP, aggregative data etc. It is useful to measure the performance of how quickly the queries are calculated or how quickly the data is loaded into BW.
51) What is entity relationship model in data modeling ?
A) An ERD(Entity Relation Diagram) that can be used to generate a physical database.
B) It is an high level data model.
C) It is a schematic that shows all the entities within the scope of integration and the direct relationship between the entities.
52) What is the data target administration task?
Data target administration task includes
a) Delete Index
b) Generate Index
c) Construct database statistics
d) Complete deletion of data target
e) Compression of the info-cube etc.
53) What are the delta options available when load from flat file?
Three options are available for delta management with flat files
1) Full upload
2) New status for changed records
3) Additive delta
54) What are the steps within SAP BI to create classes for BW?
To create classes or nodes for BW you have to follow the following steps,
a) Click on post-processing of data sources
b) Execute/Click on IMG activity
c) Select BW or any desired node
d) Click on context menu
e) Press F6 or select “Create node”
After following these steps, a new dialog box will appear, where you can insert your node or class for BW.
55) What is data ware-housing hierarchy?
To define data aggregation hierarchy can be used. It is a logical structure that use ordered levels as a means of organizing data. For instance, by using time dimension hierarchy, it is possible to aggregate data from the month level to the quarter level to the year level.
56) How will you debug errors with SAP GUI ?
To debug errors in SAP GUI you have to follow the path
a) Run Bexanalyzer
b) Business Explorer menu item
c) Installation check
This will show an excel sheet with start button, on clicking on it, it will verify the GUI installation and if there is any error you can fix it or either re-install it.
57) What is datamining concept ?
A) Process of finding hidden patterns and relationships in the data.B) With typical data analysis requirements fulfilled by data warehouses,business users have an idea of what information they want to see.C) Some opportunities embody data discovery requirements,where the business user wants to correlate sets of data to determine anomalies or patterns in the data.
58) What is scoring ?59) Usage of Geo-coordinates ?
A) The georelevant data can be displayed and evaluated on a map with the help of the BEx Map.
59) Hope you have worked on enhancements and on which userexit you worked can you explain?A) Extended the Data source 0MATERIAL_ATTR , 0PLANT_ATTR, 0MAT_PLANT_ATTR for Master Data load from R/3 to BW. Edited User exit EXIT_SAPLRSAP_002 to populate Master Data for extended fields and EXIT_SAPLRSAP_001 for transaction data to extract from R/3 to BW
60) What is the t-code for generic extractor?
61) What is infoset query?
A) InfoSet is special kind of InfoProvider. It is used to report by Joining ODS Objects and InfoObjects. InfoSets have been used in the Business Information Warehouse for InfoObjects (master data), ODS objects, and joins for these objects. The InfoSet Query can be used to carry out tabular (flat) Reporting on these InfoSets.
62) What is the purpose of aggregates?
A) Aggregates are like indices to database tables. They are rolled up data on few characteristics on which report is run frequently. They are created for performance improvement of reporting. If a report is used very extensively and its performance is slow then we can create aggregate on the characteristics used in the report, so that when the report runs OLAP processer selects data from aggregate instead of cube.
63) How you did Datamodeling in your project? Explain
A) We had collected data from the user and created HLD(High level Design document) and we analyzed to find the source for the data. Then datamodels were done indicating dataflow, lookups. While designing the datamodel considerations were given to use existing objects(like ODS and Cube) not storing redundant data, volume of data, Batch dependency.
64) As you said you have worked on Cubes and ODS,Which one is better suited for reporting? Explain and what are the drawbacks n benefits of each one
A) Cubes are best for reporting to queries. It runs faster. In ODS we can have only simple reports. If we query based on Nonkey fields(Data fields) in ODS then, report runs slower. But in ODS we can overwrite, non key fields. But we can not overwrite in Cube. This is one of the disadvantage in Cube.
65) What are the different cubes you worked in FI?
A) Please look at Business content cubes and BW documentation on them to answer this question.
66) What is delta upload? What is the use of delta upload? Data that has been changed or added is extractor or full data is extractor?
A) When transactional data is pulled from R3 system instead of pulling all the data daily(Instead of having full load), if we pull only the changed records, or newly added records, the load on the system will be very less. So where ever it is possible we have to go for delta load than full load.
67) What are hierarchies? Explain how you used in your project?
A) Hierarchies are organizing data in a structured way. For example BOM(Bill of material) can be configured as hierarchies.
68) What is t-code for CO-PA?
69) What is SID? what is the impact in using SID?
A) In BW the information is stored as SIDs. SIDs are Auto generated number assigned to each characteristic value when they are uploaded. Search on Numeric character is always faster than Alpha characters and hence SIDs are assigned for each characteristic values.
70) What is Table partitioning? What are Return Tables?
A) If we have 0Calmonth or 0Fiscper as time characteristic, then we can partition the fact table physically. Table portioning has to be supported by the Database. Oracle, Informix, IBM DB2/390 supports table partitioning. SAP DB, Microsoft SQL Server IBM DB2/400 does not support table portioning. Table partitioning helps to run the report faster as data is stored in the relevant partition.
B) In Update rule routine, If we want to return multiple records, instead of single value, we can use this return table.
71) What is the t-code for Query Monitor?
72) Apart from R/3 ,which legacy db you used for extraction ?
A) We had legacy system called CAM. CAM system had Open order information which was full load every day to OM Schedule line ODS. CAM system was connected to R3 through DB connect.
73) What are the three ODS Objects table explain?
A) ODS Object has three tables called New, Active and Change log. As soon as new data comes into ODS, that is stored in ODS. When it is activated, the new data is written to Active table. Change is written in the change log.
74) Can you explain about Start routines how you used in your project give me an example?
A) In start routine is used for mass processing of records. In start routine all the records of data package 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 nos 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.
75) In update rules for an infocube we can specify separate update rules for characteristics of each of the key figures. In which situations is the above used?
A) To be discussed(TBD).
76) Other than BW, what are the other ETL tools used for SAP R/3 in industry?
A) Informatica, ACTA, COGNOS, Business Objects are other ETL tools.
77) Does any other ERP software use BW for data warehousing.
78) What is the importance of hierarchies?
A) One can display the elements of characteristics in hierarchy form and evaluate query data for the individual hierarchy levels in the Business Explorer (in Web applications or in the BEx Analyzer).
79) Where is 0RECORDMODE infoobject used?
A) It is used in Delta Management. ODS uses ORECORDMODE info object for delta load. ORECORDMODE has values as X,D,R. In delta data load X means rows to be skipped, D & R for delete and Remove of rows.
80) What is operating concern in CO-PA?
A) An organizational structure that combines controlling areas together in the same way as controlling areas group companies together.
81) Does all the characteristics present in ODS, are key fields.
A) No. An ODS object contains key fields (for example, document number/item) and data fields that can also contain character fields (for example, order status, customer).
82) What is the use BAPI, ALE?
A) BAPI, ALE => set of programs which will Extract data from data sources. BW connects SAP systems(R/3 or BW) and flat files via ALE. BW connects with non SAP systems via BAPI.
83) What is the importance of ‘Compounding’ of infoobjects?
A) A Compound attribute differentiates a characteristic to make the characteristic uniquely identifiable. For example, in a Plant, there can be some similar products manufactured. (Plant A-- Soap,Paste,Lotion; plant B--Soap, paste, Lotion) In this case Plant A and Plant B should be made unique. So the characteristics can be compounded to make them unique.
84) Are there any limitations for BEx analyzer?
85) How does BEx analyzer connect to BW?
A) Bex Analyzer is connected with OLAP Processor. OLE DB Connectivity makes Bex Analyzer connects with BIW.
86) What is field partitioning in CO-PA?
A) Internally allocates space in database. If needed table resides in one or few partitions, then only these partitions will be selected and examined by SQL statement, therby significantly reducing I/O volume.
87) Where to check the log for warning messages appearing in activation of transfer rules?
A) If transfer rules are not defined for Info objects, then traffic lights will not be green.
88) What are the advantages of reporting on an infocube to that of reporting on an ODS?
A) Query performance will be good with Infocube. Infocube has multidimensional model where as ODS is a flat table. Aggregates and Multi provider can be built upon Infocube, which will enhance the Query performance. Aggregates and mutiproviders cannot be built on ODS.
89) How does a navigational attribute differ from other attributes in terms of linking it with the infocube?
90) How does delta update mechanism work in ODS?
A) ODS has three database tables. New Table, Active Table and Change Log Table. Initially new data are loaded and their traces are kept in Change log table. When another set of data comes, it actually compares with change log and transfers the data (delta data) into active table and also notes in Change log. Everytime the tables are compared and data is written into the targets.