SAP BW Interview Questions and Answers
What is partitioning and what are the benefits of partitioning in an InfoCube?
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.
What does Rollup do?
Rollup creates aggregates in an infocube whenever new data is loaded.
What are the inputs for an infoset?
The inputs for an infoset are ODS objects and InfoObjects (with master data or text).
What internally happens when BW objects like Info Object, Info Cube or ODS are created and activated?
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.
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.
What is the importance of 0REQUID?
It is the InfoObject for Request id. OREQUID enables BW to distinguish between different data records.
Can you add programs in the scheduler?
Yes. Through event handling.
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.
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.
When is IDOC data transfer used?
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.
What is partitioning characteristic in CO-PA used for?
For easier parallel search and load of data.
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.
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 InfoCubes in the BW system.
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?
What is the function of 'selective deletion' tab in the manage->contents of an infocube?
It allows us to select a particular value of a particular field and delete its contents.
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.
What is the effect of aggregation on the performance? Are there any negative effects on the performance?
Aggregation improves the performance in reporting.
What happens when you load transaction data without loading master data?
The transaction data gets loaded and the master data fields remain blank.
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?
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.
How many hierarchy levels can be created for a characteristic info object?
Maximum of 98 levels.
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 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.
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.
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.
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.
Can we extract hierarchies from R/3 for CO-PA?
No We cannot, “NO hierarchies in CO/PA‿.
Explain ‘field name for partitioning’ in CO-PA?
The CO/PA partitioning is used to decrease package size (eg: company code)
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.
What is the use of BW Statistics?
The sets of cubes delivered by SAP is used to measure performance for query, loading data etc., It also shoes the usage of aggregates and the cost associated with then.
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 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 are Remotecubes and how you accessed and used it in your project?
A RemoteCube is an InfoCube 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.B) Using a RemoteCube, 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 RemoteCube.
Are there any limitations for BEx analyzer?
How does BEx analyzer connect to BW?
Bex Analyzer is connected with OLAP Processor. OLE DB Connectivity makes Bex Analyzer connects with BIW.
What is field partitioning in CO-PA?
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.
What is difference between ‘saving’ and ‘activating’?
In BIW, Saving--> actually saves the defined structure and retrieves whenever required.B) Activating---> It saves and generates required tables and structures.
What does delta initialization do?
It makes BW to expect the data from Sources, after full update. It initializes the delta Update mechanism for that datasource.
What is difference between delta and pseudo delta?
Some data target and module has delta Update feature. Those can be used for delta Update of data. Say ODS, COPA are delta capable. data can be expected stage wise. After first accumulation of data, BIW expects the data in delta wise for these data target. When the other data target do not have these feature (delta update), they can be made delta capable using ODS as data target.
What is “replication of data source‿ process?
Replication of data source enables the extract structure from the source system to be replicated in the target system.
Any quality checks available for inefficient cube designs?
Huge Dimension tables make a cube inefficient.
Why not star-schema is implemented for ODS as well?
Because ODS is meant to store a detailed document for quick perusal and help make short-term decisions.
How do you transform Open Hub Data?