MSAS: Working with Levels and Hierarchies Page - 3

Creating Member groups in Dimension Levels

Member groups in a dimension level are system generated parents of collections of consecutive dimension members. End users will not be able to see any difference between ordinary members and member groups. However, member groups provide an intermediate level for drilldown between a level with few members and one with multiple members. They also help restrict the number of members in a group to 64,000 under a parent member.

Member groups can be created automatically in a regular dimension while it is being created. This option is operable only for the member groups immediately above the lowest level of the dimension. To select this option the user needs to specify this in the Specify Storage mode and create member groups step of the dimension wizard by selecting Create member groups automatically.

1. Select the dimension that will contain the member groups:
• If the dimension is shared, in the Analysis Manager tree pane, right-click the dimension, and then click Edit.
• If the dimension is private, in the Analysis Manager tree pane, right-click the cube that contains the dimension, and then click Edit. In the Cube Editor tree pane, expand the dimension to reveal its levels.
2. Create a copy of the level that contains the members that will be the children of the member groups. Create it immediately above the original. To do this, follow these steps:
1. In the editor tree pane, select the level to be copied.
2. If the properties pane is not expanded, expand it by clicking Properties beneath the tree pane.
3. In the properties pane, click the Basic tab.
4. Record the value of the Member Key Column property.
5. On the Insert menu, click Level.
6. In the Select Column dialog box, select the column recorded in Step d, and then click OK.
   
   
7. Select the new level.   
   Ads
   
8. Drag the new level to a position immediately above the original level.
9. In the properties pane, ensure that all of the new level's properties except Name have the same values as the original level.
3. In the editor tree pane, select the level in which you want to create member groups. (Select the new level from Step 2, not the original level.)
4. In the properties pane, click the Advanced tab.
5. For the Grouping property, select Automatic.
6. If you want to hide from end users the level that contains the member groups, follow these steps: In the editor tree pane, select the level that contains the member groups.
• In the properties pane, click the Advanced tab.
• Change the value of the Visible property to False.
7. In the editor, on the File menu, click Save.

Once the group is created the dimension has to be processed.

Levels derived from two columns

The column that supplies the member names of a level is selected by defining the Member name column property of the level and the members are identified by the Member Keys property. While defining the dimension, the column selected for defining the level is recorded both in the Member Name Column property and the member Key Column property. These can be changed later so that they reference different columns using the Dimension Editor or the Cube editor. When the member names of a level are derived from a column different from the keys of the members, the level itself is said to be derived from two columns.