1) Describe how you have used Excel as a compliment to BEx
Describe your level of expertise and the rationale for your self-rating (experience with macros, pivot tables and formatting
2) What is partitioning and what are the benefits of partitioning in an Info Cube ?
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 info cube, the reporting performance is enhanced because it is easier to search in smaller tables. Also table maintenance becomes easier.
3) What does Rollup do ?
Rollup creates aggregates in an info cube whenever new data is loaded.
4) What are the inputs for an infoset ?
The inputs for an infoset are ODS objects and Info Objects (with master data or text).
5) What internally happens when BW objects like Info Object, Info Cube or ODS are created and activated ?
When an Info Object, Info Cube 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.
6) What is the maximum number of key fields that you can have in an ODS object ?
16.
7) What is the specific advantage of LO extraction over LIS extraction ?
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.
8) What is the importance of 0REQUID ?
It is the Info Object for Request id. OREQUID enables BW to distinguish between different data records.
9) Can you add programs in the scheduler ?
Yes. Through event handling.
10) What is the importance of the table ROIDOCPRMS ?
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.
11) What is the importance of 'start routine' in update rules ?
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.
12) When is IDOC data transfer used ?
IDOCs are used for communication between logical systems like SAP R/3, R/1 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.
13) What is partitioning characteristic in CO-PA used for ?
For easier parallel search and load of data.
14) What is the advantage of BW reporting on CO-PA data compared with directly running the queries on CO-PA ?
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.
15) What is the function of BW statistics cube ?
BW statistics cube contains the data related to the reporting performance and the data loads of all the Info Cubes in the BW system.
16) 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 ?
No.
17) What is the function of 'selective deletion' tab in the manage->contents of an info cube ?
It allows us to select a particular value of a particular field and delete its contents.
18) When we collapse an infocube, is the consolidated data stored in the same infocube or is it stored in the new infocube ?
Data is stored in the same cube.
19) What is the effect of aggregation on the performance ? Are there any negative effects on the performance ?
Aggregation improves the performance in reporting.
20) What happens when you load transaction data without loading master data ?
The transaction data gets loaded and the master data fields remain blank.
21) When given a choice between a single infocube and multiple InfoCubes with a multi provider, what factors does one need to consider before making a decision ?
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 multi provider with many cubes since the reporting would be faster for an individual cube query rather than for a big cube with lot of data.
22) How many hierarchy levels can be created for a characteristic info object ?
Maximum of 98 levels.
23) What is open hub service ?
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 Info spoke. 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.
24 ) What is the function of 'reconstruction' tab in an infocube ?
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.
25) What are secondary indexes with respect to InfoCubes ?
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.
26) What is DB connect and where is it used ?
DB connect is database connecting piece of program. It is used in connecting third party tools with BW for reporting purpose.
27) Can we extract hierarchies from R/3 for CO-PA ?
No We cannot, “NO hierarchies in CO/PA.
28) Explain ‘field name for partitioning’ in CO-PA
The CO/PA partitioning is used to decrease package size (eg: company code)
29) What is V3 update method ?
It is a program in R/3 source system that schedules batch jobs to update extract structure to data source collectively.
30) What is the common method of finding the tables used in any R/3 extraction
By using the transaction LISTSCHEMA we can navigate the tables.
31) Differences between table view and infoset query
An InfoSet Query is a query using flat tables.
32) How to load data from one Info Cube to another Info Cube ?
Throw Data Marts data can be loaded from one Info Cube to another Info Cube.
33) Difference between extract structure and data source
- In Data source we define the data from diff source sys,where as in extract struct it contains the replicated data of data source n where in we can define extract rules, n transfer rules
- Extract Structure is a record layout of Info Objects.
- Extract Structure is created on SAP BW system.
34) What is referential integrity mechanism ?
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.
35) What is D-Management in LO ?
It is a method used in delta update methods, which is based on change log in LO.
36) What is entity relationship model in data modeling ?
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.
37) What is data mining concept ?
- Process of finding hidden patterns and relationships in the data.
- With typical data analysis requirements fulfilled by data warehouses,business users have an idea of what information they want to see.
- Some opportunities embody data discovery requirements,where the business user wants to correlate sets of data to determine anomalies or patterns in the data.
38) How does the time dependency works for BW objects ?
Time Dependent attributes have values that are valid for a specific range of dates(i.e valid period).
39) What is I_ISOURCE ?
Name of the Info Source
40) What is I_T_FIELDS ?
List of the transfer structure fields. Only these fields are actually filled in the data table and can be sensibly addressed in the program.
41) What is C_T_DATA ?
Table with the data received from the API in the format of source structure entered in table ROIS (field ROIS-STRUCTURE).
42) What is I_UPDMODE ?
Transfer mode as requested in the Scheduler of the Business Information Warehouse. Not normally required.
43) What is I_T_SELECT ?
Table with the selection criteria stored in the Scheduler of the SAP-Business Information Warehouse. This is not normally required.
44) What is Serialized V3 Update ?
This is the normal update method. Here, document data is collected in the order it was created and transferred into the BW as a batch job. The transfer sequence is not the same as the order in which the data was created in all scenarios.
45) What is Direct Delta ?
In this method, extraction data is transferred directly from document postings into the BW delta queue. The transfer sequence is the same as the order in which the data was created.
46) What is Queued Delta ?
In this method, extraction data from document postings is collected in an extraction queue, from which a periodic collective run is used to transfer the data into the BW delta queue. The transfer sequence is the same as the order in which the data was created.
47) What is Unserialized V3 Update ?
This method is almost exactly identical to the serialized update method. The only difference is that the order of document data in the BW delta queue does not have to be the same as the order in which it was posted. We only recommend this method when the order in which the data is transferred is not important, a consequence of the data target design in the BW.
48) What are the different Update Modes ?
- Serialized V3 Update
- Direct Delta
- Queued Delta
- Unserialized V3 Update
49) What are the different ways Data Transfer ?
- Complete Update: All the data from the information structure us transferred according to the selection criteria defined in the scheduler in the SAP BW.
- Delta Update: Only the data that has been changed or is new since the last update is transferred. To use this option, you must activate the delta update.
50) What is the major importance for the usage of ODS Object ?
ODS is majorly used as a staging area.
51) What is the benefit of using BW reporting over SAP Reporting ?
- Performance
- Data Analysis
- Better front end reporting.
- Ability to pull the data from SAP and Non - SAP sources.
52) Differences between star and extended star schema ?
Star schema: Only characteristics of the dimension tables can be used to access facts. No structured drill downs can be created. Support for many languages is difficult.B) Extended starschema: Master data tables and their associated fields(attributes). External hierarchy tables for structured access to data. Text tables with extensive multilingual descriptions.
53) What are the major errors in BW and R3 pertaining to BW ?
- Errors in loading data (ODS loading, Cube loading, delta loading etc)
- Errors in activating BW or other objects.
- Issues in delta loadings
54) When are tables created in BW ?
when the objects are activated, the tables are created. The location depends on the Basis installation.
55) What is a start routine and return table, how do they synchronize with each other ?
Start routine is used at update rules and return table is used to return the Value following the execution of start routine
56) 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, update routines cant.
57) What does a M table signify ?
Master table.
58) What does a F table signify ?
Fact table
59) What is data warehousing ?
Data Warehousing is a concept in which the data is stored and analysis is performed over it.
60) What is process chain and how you used it ?
- 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.
- In one of our scenario we wanted to upload wholesale price info object 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 Info Object master data table. This dependency of first uploading master data and then uploading transaction data was done through the process chain.
61) What are Remote cubes and how you accessed and used it in your project ?
- A Remote Cube is an Info Cube whose transaction data is not managed in the Business Information Warehouse but externally. Only the structure of the RemoteCube is defined in BW. The data is read for reporting using a BAPI from another system.
- Using a Remote Cube, you can carry out reporting using data in external systems without having to physically store transaction data in BW. You can, for example, include an external system from market data providers using a Remote Cube.
62) Hope you have worked on enhancements and on which user exit you worked can you explain ?
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_001 to populate Master Data for extended fields and EXIT_SAPLRSAP_001 for transaction data to extract from R/3 to BW
63) What is the t-code for generic extractor ?
RSO1
64) What is infoset query ?
InfoSet is special kind of InfoProvider. It is used to report by Joining ODS Objects and Info Objects. Info Sets have been used in the Business Information Warehouse for Info Objects (master data), ODS objects, and joins for these objects. The InfoSet Query can be used to carry out tabular (flat) Reporting on these Info Sets.
65) What is the purpose of aggregates ?
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.
66) How you did Data modeling in your project ? Explain
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 data models were done indicating dataflow, lookups. While designing the data model considerations were given to use existing objects ( like ODS and Cube ) not storing redundant data, volume of data, Batch dependency.
67) 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
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.
68) What are the different cubes you worked in FI ?
Please look at Business content cubes and BW documentation on them to answer this question.
69) 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 ?
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.
70) What are hierarchies? Explain how you used in your project ?
Hierarchies are organizing data in a structured way. For example BOM ( Bill of material ) can be configured as hierarchies.
71) What is t-code for CO-PA ?
KEB0
72) What is SID? what is the impact in using SID ?
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.
73) What is Table partitioning? What are Return Tables ?
- 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 DB1/390 supports table partitioning. SAP DB, Microsoft SQL Server IBM DB1/400 does not support table portioning. Table partitioning helps to run the report faster as data is stored in the relevant partition.
- In Update rule routine, If we want to return multiple records, instead of single value, we can use this return table.
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