IBM Cognos, User Manual, Page: 117 / 411

missing and, by default, be reported as zero. If the special category has only one
child, you can either supply a value for the special category or accept the value
taken from the child.
Procedure
1. After you have imported the structural and transactional data sources into your
model, open the
Data Source property sheet for the transactional data source
and click the General tab.
2. Click the Contains externally rolled up measure values check box and click
OK .
3. Add the measures to the Measures list.
4.
Open the
Dimension
property sheet for each dimension that is to have
externally rolled up measures applied to it and click the
General
tab.
5. In the External rollup column box, click Add to specify which transactional
column contains the category codes the measure values will map to.
6. In the New Association dialog box, select Source from the Association role
drop-down list, and click More to select the external rollup column. Click OK
three times.
7. For each externally rolled up measure, open the Measure property sheet and
click the Rollup tab.
8. In the Regular rollup box, click External .
Note: For date dimensions or dimensions without unique source values,
specify the column from which category codes can be assigned in order to
make these codes unique in the dimension, as follows:
v
Open the Level property sheet for each level in each dimension with
externally rolled up measures.
v
In the Associations box, select the source column and click the ellipsis button
( ... ) to open the New Association dialog box.
v
In the New Association dialog box, select the Association role, and then
click the More button to select the structural source column to map to the
level.
v If you are using allocations, on the Column property sheet, set the Degree of
detail
to specify the lowest level to which the associated measure applies.
9. Create the cube by clicking Create PowerCubes from the Run menu.
Set a Time State Rollup Function for Measures
The time state for a measure is its value at a specific point in time, such as the
inventory quantity of an item at the end of the month.
You set the Degree of detail property to the lowest level of detail for the
transaction; that is, the values at the bottom of the hierarchical tree. For example, if
your source file contains daily transactional records, the degree of detail is
Day .
You can use any of the following Time state rollup functions to summarize the
values from your non-measure columns:
Minimum
,
Maximum
,
First period
,
Last
period
,
Current period
, and
Average
.
There are several constraints that apply when defining time-state rollups:
v
Regular rollup is not applied to a time dimension if Time state rollup is
selected. Also, you cannot apply summarized views to a time dimension when
the model contains a measure with
Time state rollup applied.
Chapter 5. Modeling Your Key Performance Measures
103