Creating a Virtual Cube to Control Presentation and Augment Security
We mentioned earlier
that another strength of a virtual cube lies in its capacity to act as an
adjunct to an overall security strategy. This attribute makes a virtual cube
useful when a part (or parts) of a cube's information is (are) sensitive and not
suitable for all users. A virtual cube (which, as we have seen, we can easily
create from an existing cube) provides a means of omitting the sensitive
information.
We can then create two
security roles: the first role containing the users permitted to see the
sensitive information, and the second containing the remaining (disallowed)
users. We then simply grant the first role access to the original (full) cube
and the second role access to the virtual cube. In this manner, both sets of
information consumers have access to the information they need to perform their
respective functions but are restricted from, or given access to, the
sensitive data as is appropriate.
First, let's set the
stage with a realistic scenario: The Warehouse cube (another of the
sample cubes that are put in place with the Typical Analysis Services
implementation) contains six cube dimensions, a larger number of shared
dimensions, and seven measures. Let's say we want to present the general
information in the cube to two general sets of information consumers: those
who are allowed to see all data (we'll call them the Corporate group); and
those (the Operations group) who are allowed to see only enough of the
operational data to complete their daily tasks (the cost and logistic
information), but who do not need to be concerned with the revenue information
(which we will assume for our immediate purposes to be included in the Store
Invoice, Warehouse Sales, and Warehouse Profit measures).
We will create a subset
of the existing Warehouse cube to meet the needs of the Operations
group, for starters.
- From the Analysis Manager console, right-click the Cubes
folder within the FoodMart 2000 database.
- Click New Virtual Cube on the context menu, as
we did in our first exercise.
The Virtual Cube
Wizard Welcome Dialog appears, once again.
- Click Next.
The Select the Cubes to Include in the Virtual Cube dialog
appears.
- Double-click the Warehouse cube to select and
move it from the Available Cubes list to the Virtual Cubes
Include list.
The dialog appears as shown below, after our selection.
Illustration 19: Our Selection: Cubes to Include in the Virtual Cube Dialog
- Click Next.
- Select the following measures:
- Supply Time
- Warehouse Cost
- Units Shipped
- Units Ordered
Our selections appear
in the Selected Measures list of the dialog.
- Click the Supply Time measure once.
- Press F2 to enter the Edit mode.
- Change the Supply Time measure name to Lead
Time.
- Click the Warehouse Cost measure once.
- Press F2 to enter the Edit mode.
- Change the Warehouse Cost measure name to
simply Cost.
The Select the
Measures for the Virtual Cube dialog appears as shown below, after we have
made our changes.
Illustration 20: The Measures as Modified
- Click Next.
Page 8: Creating a Virtual Cube (Continued)
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