SAP-BW interview questions part-IV

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.