You design a Business Intelligence (BI) solution by using SQL Server 2008. You design a solution that analyzes the usage of discount vouchers issued by the company. The data warehouse of the company contains a dimension table named Vouchers. The dimension table contains two columns named VoucherNumber and CustomerFullName. A value for the CustomerFullName column is not available till the voucher is used. You need to configure the Slowly Changing Dimension transformation to load the Vouchers dimension even if there is a NULL value in the CustomerFullName column.
What should you do?
A.
Enable the support for inferred members.
B.
Set the Change Type option to Fixed Attribute for the CustomerFullName column.
C.
Set the Change Type option to Historical Attribute for the VoucherNumber column.
D.
Set the Change Type option to Changing Attribute for the VoucherNumber column.
Explanation:
Tip: "Slowly Changing Dimension … NULL" = "inferred members"The Inferred Dimension Members page lets us specify whether we can infer information for dimension members that do not yet exist. When the wizard completes, it adds a number of transformations to the package. These additional transformations provide the functionality to make the slowly changing dimension update work properly.
(McGraw-Hill – Delivering Business Intelligence with Microsoft SQL Server 2008 (2009))http://msdn.microsoft.com/en-us/library/ms186969.aspx
Inferred Dimension Members (Slowly Changing Dimension Wizard)
Use the Inferred Dimension Members dialog box to specify options for using inferred members. Inferred members exist when a fact table references dimension members that are not yet loaded. When data for the inferred member is loaded, you can update the existing record rather than create a new one.
Inferred member indicates that the row is an inferred member record in the dimension table. An inferred member exists when a fact table references a dimension member that is not yet loaded. A minimal inferred-member record is created in anticipation of relevant dimension data, which is provided in a subsequent loading of the dimension data. The Slowly Changing Dimension transformation directs these rows to an output named Inferred Member Updates.