Defining Columns - IBM Cognos User Manual

v After Cognos Transformer reads your purely structural data sources and
v For structural data sources that frequently change, you can set the timing to
v For transactional data sources, where the measure values are constantly
Procedure
1. In the Data Sources list, right-click the data source for which you want to
2. On the General tab of the Data Source property sheet, under the Timing box,
3. Select the PowerCube creation check box and choose what will occur when
4. Click OK.

Defining Columns

Even if you build your dimensions and measures from in-scope data source
columns, you may have to change your column definitions to ensure that your
model delivers solid business value.
Source columns contain not only the text, date, and code values that become the
categories in your model, but also the numeric values that you select as measures,
or performance indicators. Data columns can also contain values that you may
want to use as alternate labels, short names, or textual descriptions for categories.
If you need more structural or numeric information in your model than is available
from your source data, you may be able to add it by using calculated columns. For
more information about the functions you can use when creating calculated
columns, see Appendix F, "IBM Cognos Transformer Expression Editor," on page
355.
populates your model with data for the required category structure, you can
change the timing so that these static categories are not regenerated every time
you create the PowerCube.
update the categories whenever you create the PowerCube.
changing, you can select the Default method of PowerCube creation.
control the timing and click Properties.
select the Generate categories check box.
This will cause the data source to be queried whenever categories are
generated.
cubes are created or updated:
Default
v
Cognos Transformer reads all columns in the source that relate to levels in
the model to see if they are associated with measures. If the source is purely
structural, the cube is not created or updated, and an error message appears.
Use this option in a production environment for transactional data sources
and structural data sources that contain non-static data.
Generate categories only
v
Cognos Transformer queries only for structural information when the Create
Selected PowerCube and Update Selected PowerCube commands run. If
there are measures in any of the source files, they are not retrieved.
Create the PowerCubes
v
Cognos Transformer queries the source and creates or updates the cubes,
even if the source lacks measures. In a design and development environment,
use this option to override error messages and continue processing.
Chapter 3. Data Sources for Your Model
47