Dimension Attributes: Introduction and Overview, Part III - Page 2

May 15, 2008

Procedure: Examine Further Attribute Properties in Analysis Services 2005

Having continued our examination of the properties that define and support a representative attribute in Dimension Attributes: Introduction and Overview, Part II, we focused upon the Basic group of attribute properties within our practice session. In the practice procedures that follow, we will examine the properties that are classified within the Misc group of the same attribute with which we worked in Part I & Part II, namely Geography Key, one of the attributes belonging to the Geography dimension.

We will conduct our practice sessions within the SQL Server Business Intelligence Development Studio, from which we will perform our examination of attribute properties within our Analysis Services database, ANSYS065_Basic AS DB. In Dimension Attributes: Introduction and Overview, Part I, we noted that to access the properties settings for attributes within a representative dimension, we needed to open that dimension within the Dimension Designer first. (Recall that, because database dimensions, and not cube dimensions, contain attributes, we access properties supporting dimension attributes via the Dimension Designer, and not the Cube Designer.)

The tabs of the Dimension Designer open.

We noted in Part I that five attributes appear within the Attributes pane of the Dimension Structure tab. The attributes belonging to the Geography dimension appear as shown in Illustration 4.

We will continue our examination of the properties associated with attributes by re-entering the Geography Key attribute, as before.

Overview of the Attribute Properties

As we noted in previous articles of this subseries, Analysis Services exposes many properties that determine how dimensions and dimension attributes function. We can review the properties for our selected attribute, Geography Key, within our sample UDM, by taking the following steps.

The Properties pane appears for the Geography Key attribute. (The Properties pane likely appeared when we selected the Geography Key attribute within the Dimensions pane, by default, below the Solution Explorer. The design environment can, of course, be customized in many ways to accommodate our local development needs.)

We can, at this stage, see the thirty DimensionAttribute properties for the Geography Key attribute within the Properties pane. We examined the first eleven properties, the members of the Advanced properties group, in Dimension Attributes: Introduction and Overview, Part I. We noted that these properties include the following:

• AttributeHierarchyDisplayFolder
• AttributeHierarchyEnabled
• AttributeHierarchyOptimizedState
• AttributeHierarchyVisible
• DefaultMember
• DiscretizationBucketCount
• DiscretizationMethod
• EstimatedCount
• IsAggregatable
• OrderBy
• OrderByAttribute

The five Basic properties (which we examined in Part II), appearing underneath the Advanced properties group, include the following:

• Description
• ID
• Name
• Type
• Usage

The Misc group comes next, (we examined them in this article), and includes the following four properties:

• AttributeHierarchyOrdered
• GroupingBehavior
• InstanceSelection
• MemberNamesUnique

Beneath the Misc group in the Properties pane lies the Parent-Child group, which includes the following five properties:

• MembersWithData
• MembersWithDataCaption
• NamingTemplate
• RootMemberIf
• UnaryOperatorColumn

Finally, the five Source properties, appearing underneath the Parent-Child properties group, include the following:

• CustomRollupColumn
• CustomRollupPropertiesColumn
• KeyColumns
• NameColumn
• ValueColumn

The Properties pane for the Geography Key attribute, with the Misc properties group (which we will examine in the practice session that follows) expanded, appears as shown in Illustration 6.

Having completed our review of the Basic attribute properties in Part II, let’s examine the next attribute properties group that appears for Geography Key.

Examine Attribute Properties: Misc Properties

Let’s take a look at the four available Misc properties for our chosen attribute example. We will again discuss the purpose of each property, examining or discussing, in most cases, possible settings with which we can come into contact within the context of the respective property.

Misc Property: AttributeHierarchyOrdered

One of several attribute properties that define and control the behavior of the attribute hierarchy, the AttributeHierarchyOrdered property setting specifies whether the members of the attribute hierarchy are ordered. The setting options are, unsurprisingly, True or False (with a default of True). While it might seem intuitive to order members most of the time, we can use this setting to conserve processing power in certain cases: if we know in advance that the associated attribute hierarchy will not be used for querying (or it is otherwise enabled, but not often used), processing time can be saved by changing this property value to False.

Misc Property: GroupingBehavior

The value we select for the GroupingBehavior property can be used to provide a “hint,” or indicator, to a client application.

The two selection options, EncourageGrouping (the default) and DiscourageGrouping appear. As we have noted, the setting is relevant only from the perspective of a targeted client application that is designed to take advantage of the setting in the first place.

Misc Property: InstanceSelection

The value we supply to InstanceSelection is similar to that which we provide to the GroupingBehavior property, in that it can be used to provide a “hint,” or indicator, to a client application. In short, the value selected here specifies the recommended means by which a client user interface should allow selection of a member. That is, the selected setting (there are five options) provides direction to the targeted client application(s) about how they should present a list of items to users, based largely upon the expected number of items within the list involved.

The five selection options appear as follows:

• None: (Default) InstanceSelection not enabled / applicable.
• DropDown: Appropriate for situations where the number of items is small enough to display within a dropdown list.
• List: Appropriate for situations where the number of items is too large for a dropdown list, but not large enough to require filtering.
• Filtered List: Most useful in scenarios where the number of items is large enough to require users to filter the items to be displayed.
• Mandatory Filter: Appropriate for situations where the number of items is so large that the display must always be filtered.

Misc Property: MemberNamesUnique

The MemberNamesUnique property setting specifies whether member names in the attribute hierarchy must be unique. The setting options are True or False (with a default of False). The setting affects how member unique names are assigned.

Having completed our review of the members of the Misc properties group, we will conclude this part of our examination of attribute properties. We will extend our introductory examination of dimension attributes, specifically continuing our discussion with the Parent-Child and Source groups of properties, within subsequent parts of this article.

Conclusion

In this, the third part of a multi-part article introducing dimension attributes, we continued our current subseries focusing upon dimensional model components, with an objective of discussing the associated concepts, and of providing hands-on exposure to the properties supporting each. We reviewed our initial introduction to the dimensional model and summarized its role in meeting the primary objectives of business intelligence. Next, we provided a brief review of dimension attributes in general.

We overviewed many of the general characteristics and purposes of attributes, including their names, and the names of the groups within which each is classified. We then continued our focus upon the properties underlying them, based upon the examination of a representative attribute within our sample cube. In this article, we extended our discussion beyond the Advanced group of properties, which we began in Part I, and the Basic group of properties, with which we continued in Part II and examined the attribute properties belonging to the Misc group, including what they define and support, and how we can manage them. We will continue our examination of attribute properties, this time for those that constitute the membership of the Parent-Child properties group, in the next part of this article.

» See All Articles by Columnist William E. Pearson, III

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