You design a Business Intelligence (BI) solution by using SQL Server 2008. You create a SQL Server 2008 Analysis Services (SSAS) solution that has a dimension table named DimCustomer.
The DimCustomer table has the following attributes:
-Gender
-Address
-Marital Status
-Phone Number
You discover that DimCustomer takes a long time to process. You need to reduce the processing time of DimCustomer. You also need to reduce the disk space required for the DimCustomer dimension table.
What should you do?
A.
Set the ProcessingGroup property of DimCustomer to ByTable.
B.
Set the ProcessingGroup property of DimCustomer to ByAttribute.
C.
Set the AttributeHierarchyEnabled property of the Gender and Marital Status attributes to false.
D.
Set the AttributeHierarchyEnabled property of the Phone Number and Address attributes to false.
Explanation:
Tip: “reduce the disk space required” = “AttributeHierarchyEnabled … Phone and Address”http://msdn.microsoft.com/en-us/library/ms166717(SQL.90).aspx
Hiding and Disabling Attribute Hierarchies
By default in Microsoft SQL Server 2005 Analysis Services (SSAS), an attribute hierarchy is created for every attribute in a dimension, and each hierarchy is available for dimensioning fact data. This hierarchy consists of an All level and a detail level containing all members of the hierarchy. As you have already learned, you can organize attributes into user-defined hierarchies to provide navigation paths in a cube. Under certain circumstances, you may want to disable or hide some attributes and their hierarchies. For example, certain attributes such as social security numbers or national identification numbers, pay rates, birth dates, and login information are not attributes by which users will dimension cube information. Instead, this information is generally only viewed as details of a particular attribute member. You may want to hide these attribute hierarchies, leaving the attributes visible only as member properties of a specific attribute. You may also want to make members of other attributes, such as customer names or postal codes, visible only when they are viewed through a user hierarchy instead of independently through an attribute hierarchy. One reason to do so may be the sheer number of distinct members in the attribute hierarchy. Finally, to improve processing performance, you should disable attribute hierarchies that users will not use for browsing.
The value of the AttributeHierarchyEnabled property determines whether an attribute hierarchy is created. If this property is set to False, the attribute hierarchy is not created and the attribute cannot be used as a level in a user hierarchy; the attribute hierarchy exists as a member property only. However, a disabled attribute hierarchy can still be used to order the members of anotherattribute. If the value of the AttributeHierarchyEnabled property is set to True, the value of the AttributeHierarchyVisible property determines whether the attribute hierarchy is visible independent of its use in a user-defined hierarchy.