Today i will illustrate a significant concept--SID Table in BW.

    First let's pay attention to the explain about it. SID is Surrogate ID Table.The

importance of SID table is it makes master data independent of Dimension

table.This is an extended star schema.Fact table is connected to Dimension

tables, eachDimension table is connected to a SID table, which in turn connect the

corresponding master table .Suppose say if another fact table needs the same

master data table,it can connect to the master data table with the help of its

SID table, by this  one master data table can be shared by 2 fact tables. So no

redundancy of master table occurs. In classical star schema master data table

is present with in dimension table ,here redundancy occurs. because master

data table is duplicated.

   So now i will give a sample that i think it's a good method to understand it.

  Customer A ( C001) sells a  material(M001) to Company(CP001) and get

 revenue 10NTD.

 The following picture can illustrate it.

After you get the Customer's master data id ,  the related information about it will

be easy for you. you can access the P table , T table and H table.