Thursday, 5 February 2015

Technical round SAP BW Interview Questions and Answers (Part7)

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.
More Questions & Answers :-
Part1  Part2  Part3  Part4  Part5  Part6  Part7  Part8  Part9

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