IBM Cognos Dynamic Cubes

Chapter 6. Virtual cubes 141

6.3.3 Multiple fact tables

With virtual cubes, you can build a cube that will share dimensions between cubes, and build

reports that use facts from multiple cubes. One example is to have a virtual cube that includes

a cube with actual values and a cube with target or budget values.

Into the virtual cube You can build calculated measures that reference measures from both

source cubes. One example is a measure that calculates the variance from plan by

subtracting the budget or the target plan values from the actual values. If the remainder is a

positive number, then the variance exceeded the budget or target plan. Another example is a

measure that takes that variance and compares it to the budget of the target plan value to

produce a percent of plan measure.

6.4 Managing virtual cubes

Chapter 5, “Administering dynamic cubes” on page 115 describes tasks involved in Dynamic

Cubes administration. Virtual cubes administration follows the same procedures described in

that chapter. This section describes additional administration tasks required by virtual cubes.

6.4.1 Verifying virtual cube dependency

Use the following steps to verify the list of source cubes that are associated to a virtual cube:

1. Go to IBM Cognos Administration.

2. Select Status.

3. Select System.

4. Select the server.

5. Select the dispatcher.

6. Select QueryService.

7. Select the virtual cube.

142 IBM Cognos Dynamic Cubes

In the metrics section, a metric named Source cubes lists the source cubes that are

associated to the selected virtual cube, as shown in Figure 6-9.

Figure 6-9 Source cubes associated to virtual cube

To see the cubes that other cubes depend on for a selected source cube, select the source

cube; in the metric section, a metric named Dependent cubes lists the cubes that depend on

the selected cube, as shown in Figure 6-10.

Figure 6-10 Dependent cubes