SAP BW ....Basics ....3

Q.What are the types of info source?Ans.transactional, attributes,text and hierarchy.

Q.What is the communication structure?Ans. It is an independent structure created from info source; It is independent of the source system/data source.

Q.What is communication structure?Ans.The transactional rules for data from source system to info source/ communication structure.

Q.What is global transfer rule?Ans.This is a transfer routine (ABAP) defined at the info object level; this is common for all source systems.

Q.what are the options available in transfer rule?Ans.Assign info object, assign a constant, ABAP routine or a formula(from version 3.x). example are
a.Assing info object – direct transfer, no transformation
b.Assign a constant – for example if you are loading data from a specified country in a flat file, you can make the country constant and assign the value
c.ABAP routine- for example if you want to do some complex string manipulation; assume that you are getting a flag file from legacy data and cost centre is in a field and you have to “message’the data to get it; in this case use ABAP routine.
d.for simple calculations use formula- for example you want to convert all lower case letters to upper case; use the TOUPPER formula.

Q. Give some important formula available?Ans.Concatenante, sub string, condense, Left/right (n characters), l_trim, r_trim, replace, date routines like DATECONV, date_week, add_to_date, date_diff, logical functions like if and;

Q. when you do to the ABAP code for rule, what are the important variables you will use?Ans.
a. RESULT – this gets the result of the ABAP code
b. RETURN CODE-You set this to value 0 if everything is Ok; else this record is skipped.
c. ABORT- set this to a value not 0, to abort the entire package

Q. what is the process of replication?Ans.This copies the data sourxce structures from R/3 to BW.

Q.What is the update rule?Ans. Update rule defines the transformation data from the communication structure to the data targets; this is independent of the source systems/ data sources.

Q.What are the options in update rule?a.one to one move of info objects
b.constant
c.look for master data attributes
d.formula
e. routine(ABAP)
f.Initial value

Q.What are the special convertions for time in update rule?Ans.Time dimensions are automatically converted; for example if the cube contains calendar month and your transfer structure contains date, the date to calendar month will be converted automatically.

Q.What is the time distribution option in update rule?Ans.This is to distribute data according to time; for example if the source contains calendar week and the target contains the calendar day, the data is split to each calendar day. Here you can select either the normal calendar or the factory calendar.

Q.what is the return table option in update rules for key figures?Ans:- Usually the update rule sends one record to the data target; using this option you can send multiple records; for example if we are getting total telephone examples for the cost centre, you can use this to return telephone expenses for each employee ( by dividing the total expenses bythe total number of employees in the cost centre) and creating cost record for each employee in the ABAP code.

Q.What is the start routine?Ans.The first step in the update process is to call start routine; use this to fill globalvariables to be used in update routines.

Q.How would you optimize the dimensions?Ans. Use as many as dimensions as possible for performance improvement ; for examplefor example assume that you have 100 products and 200 customers; if you make one dimension for both, the size of the dimension will be 20,000; if you make individual dimensions, then the total number of rows will be 300. Even if you put more than one characteristic per dimension, do the math considering worst case scenario and decide which characteristics may be combined in a dimension.