Establishing Properties to Manage Unknown Members in Analysis Services 2005
restate the business requirement underlying our practice example, as we
established in Part I,
we have received a request for assistance from representatives of our client,
the Adventure Works organization (the details of which we describe in
the first half of our article). In
short, our client colleagues have requested an introduction to the management
of Unknown Members within their implementation of Analysis Services,
stating that they wish to know more about the mechanism behind this process
(they already understand some of the rudiments of default operation by Analysis
Services in this regard). Moreover, they feel that they need some hands-on
guidance in adding a couple of new attributes to their Product
dimension, upon which they intend to base a new user-defined hierarchy
that they have determined they need to support new reporting and analysis requirements
that have been recently requested.
listening carefully to the needs enumerated by our colleagues, we proposed in Part
I to provide an introduction to Unknown
Members in Analysis Services; to provide insight as to the default
operation of the Analysis Server; and to provide practical guidance in
manually managing Unknown Member property settings, via the respective
settings that we establish among the new attribute members and
hierarchical structure we help them to create and configure. Once our client
colleagues agreed that the proposed approach should meet their immediate requirements,
we begin our introduction and set about the assembly of our example to
illustrate both default and manual management of Unknown Members within Analysis
NOTE: Our steps in creating a sample basic database within
which to perform the steps of our practice sessions are detailed in Part
I. Before you can proceed with the
practical steps below, you will need to accomplish the steps outlined in
creating and enhancing the sample cube in Part
Procedure: Continue Working with Properties to Manage Unknown Members in Analysis Services 2005
In the practice session that began
in Part I, we first examined the properties that support
management of Unknown Members. We then added attributes to a
dimension, based upon tables that we added to the underlying data source
the sample Analysis Services database / UDM we had prepared. We then examined
the mechanics behind the default exclusion of unmatched attribute
members within dimension processing.
In this half of the practice
session, we will resume where we left off at the end of Part I, enabling and configuring the
associated properties for the dimension and dimension attributes that we
have added, while discussing our options and the respective results. Finally,
we will manage error handling for the member key attribute involved.
We will perform our practice
session within the SQL Server Business Intelligence Development Studio, as
before, from which we will perform select steps of managing Unknown Members
within the Analysis Services database we created in Part I,
ANSYS063_Basic AS DB.
Reopen SQL Server Business Intelligence
Close the Start
page, if desired.
AS DB database
with which we worked in Part
I is open,
and appears within the Solution Explorer.
Note: For the steps involved in completing the above, see Part I.
re-open the Dimension Designer for the Product dimension, where
we left off in Part I,
and set about modifying the way that Analysis Services manages Unknown
Members by default.
Analysis Services Default Management of Unknown Members through Associated
We will next examine modification of Analysis Services
default management of Unknown Members through the modification of
associated property settings. First, we will enable the UnknownMember
property of the Products dimension. We will then set a value for the UnknownMemberName
property, to generate a name that is more useful to our client colleagues than
a simple Unknown. Next, we will set the NullProcessing
property for the Subcategory and Model Name attributes to UnknownMember.
Our next steps will surround attribute relationships:
We will establish the Category attribute as a related attribute of the Subcategory
attribute, and we will then establish the Product Line attribute as a
related attribute of the Model Name attribute. Our intent with the
steps will be to enforce the use of the specified Unknown Member name
value for any Product that has a key resident in the fact table, but
which has no matching key within the SubcategoryKey column with which we
were working in the earlier section Create New Attributes within the
Product Dimension upon Which to Establish Unknown Member Management within the
Within the Solution
Explorer, right-click the Product dimension (expand the Dimensions
folder as necessary).
on the context menu that appears, as depicted in Illustration 1.
1: Opening the Dimension Designer ...
tabs of the Dimension Designer open.
Click the Dimension
Structure tab, if it has not already appeared by default.
Ensure that Product,
atop the Attribute pane, is selected to cause the dimensions Properties
window to appear (by default in the lower right corner of the design
Within the Properties
window for the Product dimension, change the UnknownMember property
value (within the Advanced properties section of the window) to Visible.
value for the UnknownMemberName property (just beneath the UnknownMember
property value) to Assembly Components.
window for the Product dimension appears, with our modifications, as
shown in Illustration 2.
2: Our Modifications to the Product Dimension Property Settings
Modifying the UnknownMember property from None
(which means that the property is disabled for the dimension) to either Visible
or Hidden enables the property. Our input of Assembly Components
to the UnknownMemberName property assigns our choice of Unknown
Member name value to any Product that has a key resident in the fact
table, but for which the Analysis Server determines that no matching key
exists within the SubcategoryKey column of the associated dimension
table. (This effectively creates what I refer to as an orphan cage.)
Now, lets take a look at the relationships that exist
between certain Product attributes.
following attributes within the Attributes pane of the Dimension
Structure tab for the Product dimension.
expanded attributes appear as depicted in Illustration 3.
Illustration 3: Expanded
Product Attributes in the Attributes Pane
Within the expanded attributes, we note that Product
Line is related to the Model Name attribute (meaning, too, that it
is indirectly linked to the Product Name key attribute). We can see that
no relationships have been defined for the Subcategory attribute.
Moreover, we see that Category attribute is linked to the Product
Name attribute directly through the key attribute.
Our next steps will allow us to enforce the use of our
newly specified Unknown Member name value for any Product that
has a key resident in the fact table, but which has no matching key within the SubCategoryKey
column with which we worked earlier. We will establish a relationship between the
Category attribute and the Subcategory attribute, and then we
will establish the Product Line attribute as a related attribute of the Model
Drag the Category
attribute relationship from the Product Name attribute to the Subcategory
attribute, shown in Illustration 4.
Illustration 4: Modifying
the Relationship from Product Name to Subcategory ...
By taking the above steps, we have linked the Category
attribute to the rows in the fact table through the Subcategory
attribute, which in turn is linked to the rows in the fact table through the Product
In the Attributes
pane, click / select Subcategory.
10. Click the ellipsis button (...)
in the KeyColumns property cell (located within the Source
section) in the Properties window, as depicted in Illustration 5.
Illustration 5: Modifying
KeyColumns Properties for Subcategory ...
11. In the DataItem Collection
Editor dialog that next appears, change the NullProcessing property
to UnknownMember, as shown in Illustration 6.
Illustration 6: Modifying
the NullProcessing Property to UnknownMember ...
12. Click OK to accept our
modification and to dismiss the DataItem Collection Editor dialog.
13. Click / select Model Name within
14. Click the ellipsis button (...)
in the KeyColumns property cell in the Properties window, as we
did for the Subcategory attribute earlier.
15. In the DataItem Collection
Editor dialog that next appears, change the NullProcessing property
to UnknownMember, once again.
16. Click OK to accept our
modification, once again, and to dismiss the DataItem Collection Editor
As we have discussed in earlier sections, these
modifications dictate how Analysis Services handles any nulls it encounters,
during processing, for either or both of the Subcategory attribute or
the Model Name attribute. Our selection of the UnknownMember
option for the NullProcessing property means that the Unknown Member
value (whatever we dictate that to be) will be substituted for the key value.
Hierarchies based upon these members will thereupon reflect the new grouping
for the Unknown Members.