Attribute Member Values in Analysis Services - Page 2

Procedure: Examine Attribute Value Property Settings in Analysis Services 2005

In the practice procedures that follow, we will select and examine a representative dimension attribute within the sample cube, and then focus upon the Value property settings that define and support the selected attribute. We will perform our practice sessions within the SQL Server Business Intelligence Development Studio, from which we will examine the dimension attribute Value property within our Analysis Services database, ANSYS065_Basic AS DB.

In Dimensional Model Components: Dimensions Part I and II, and Dimensional Attributes: Introduction and Overview Parts I through V, respectively, we overviewed the properties underpinning Database and Cube dimensions, and then examined the properties supporting dimension attributes. In Attribute Member Keys – Pt I: Introduction and Simple Keys, and in Attribute Member Keys – Pt II: Composite Keys we focused upon those properties for a simple attribute Key and a composite attribute Key, respectively. Finally, in Attribute Member Names, we concentrated upon the underlying properties for the settings underlying the attribute member Name. Just as we did in those articles, we will examine the detailed settings for a representative attribute member here, concentrating on those settings within the context of the member Value. To access these settings for the attribute member within a representative dimension, we will need to open that dimension within the Dimension Designer first.

The tabs of the Dimension Designer open.

The attributes belonging to the Time dimension appear as depicted in Illustration 4.

We note that eight attributes appear within the Attributes pane. Let's get some exposure to the Value property settings associated with attribute members by examining a representative member among the attributes we see here.

Review Attribute Value Property Settings

In Dimensional Attributes: Introduction and Overview Part V, and as a part of our more detailed exploration in Attribute Member Keys – Pt I: Introduction and Simple Keys, and in Attribute Member Keys – Pt II: Composite Keys we discovered that, within the Source properties of every attribute member lays the Value property. Let’s examine the property and the underlying ValueColumn settings for the Month Name attribute, which is supported by a composite key within the sample Analysis Services database, by taking the following steps.

The Properties pane appears for the Month Name attribute. (The Properties pane likely appeared when we selected the Month Name attribute within the Attributes pane, by default, below the Solution Explorer. It also may have been hidden, set up to “float” within the Studio, or to be anchored elsewhere.) The design environment can, of course, be customized in many ways to accommodate your local environment and development needs.)

The expanded Source properties group of the Properties pane for the Month Name dimension attribute appears as shown in Illustration 7.

Let's take a look at the Value property (and its “subproperties”), as relevant to the Month Name attribute, discussing the purpose of the property, and examining possible settings with which we can come into contact.

Source Property: ValueColumn

Much like the KeyColumns property, which we examined in Attribute Member Keys – Pt I: Introduction and Simple Keys, and Attribute Member Keys – Pt II: Composite Keys, the value we select for the ValueColumn property specifies a column within the underlying data source. The ValueColumn property specifies the column containing the attribute member Value.

We note that the setting box currently contains “(none)”, indicating that the setting is not pointed to any column within the dimension table at present.

The Object Binding dialog appears, with highlighted Column binding defaulted to the top column in the Source column list.

As we have noted in other articles of this series, the Object Binding dialog is used throughout the Business Intelligence Development Studio to edit / add the column binding of data items associated with properties of various Analysis Services objects. The Object Binding dialog is typically made available for single column selection options, where selection is made by simply clicking the appropriate column within the Source column list.

Because the ValueColumn setting of our example dimension attribute (along with the ValueColumn settings in the other attributes of our sample environment) has been left at default of “(none)”, we will assign a table / column combination to enable the underlying settings for the property, so as to permit our further review of each.

We see that the ValueColumn setting, along the bottom of the Properties pane, is now populated with “DimTime.MonthNumberOfYear (UnsignedTinyInt)”. Unlike the attribute member Name (NameColumn setting), which is converted to a string in Analysis Services, the attribute member Value (ValueColumn setting) retains the data type of the underlying data column. Moreover, we note that the underlying settings for the property have now become enabled (a “+” sign has appeared alongside the ValueColumn label).

The TableID and ColumnID settings appear, as depicted in Illustration 10.

As we can see, the first of the displayed DimTime.CalendarYear DataItem properties, Source, expands to make available the TableID and the ColumnID boxes, where we can also specify the location of the Value within the underlying database. If we click on the Source label, or on the box to its right, an ellipses (...) button becomes enabled. This affords us another access point to the Object Binding dialog we saw earlier, where we can, once again, select the Table and Column that we want.

Once we have selected the TableID, we can select from a context-sensitive list of columns via the ColumnID selector, immediately underneath the TableID selector, as partially depicted in Illustration 12.