IBM Cognos User Manual page 155

If a drill-through filter applies to a level that was not declared unique in the
model, the parameters passed to the target component must contain information
for that level and for each ancestor level until a unique level or the highest level in
the dimension is reached.
In PowerPlay-to-Impromptu drill-through operations, this is automatic. For
example, if a category called Burlington belongs to the level City, which was not
set to Unique on the Level property sheet, the filter contains City=Burlington plus
the next higher level, State=Massachusetts.
For time dimensions, measure values are specified only for the most detailed leaf
categories. Categories in Cognos Transformer time dimensions are expressed as
ranges from the first to the last descendant. For example, the year 2006 is
represented as 20060101-20061231.
For special categories and categories added manually, all child categories are
handled successively until the source level is reached.
Add or Remove Drill-through Targets
Because cubes and other drill-through files may be created in different places at
different times, their data and related information, or metadata, may not always
match the information in the original cube. Ensure that you are linking to the most
up-to-date information.
When a model is based on an Impromptu Query Definition (.iqd) file, the
corresponding Impromptu reports (.imr) automatically appear in the drill-through
list for each measure in the source. You can remove some or all of these reports
from the Measure property sheets, or add additional reports that are not associated
with the original source.
To change targets for all measures in a cube at once, use the Drill Through tab on
the PowerCube property sheet.
To meet the needs of various users, you may need to set up multiple drill-through
targets:
v Drill through from a higher-level cube, showing the results for an entire product
line, to a cube that has the same measures and dimensions but has additional
levels in the Product dimension.
Users can drill through to the detailed cube to analyze results based on different
attributes, such as color or model.
v Drill through to a cube having the same degree of detail, but differing
dimensions.
The drill-through cube may be separated from the original cube in time and
space. For example, your regional office maintains client addresses in a
supported target report. Add this report to the drill-through list on the
PowerCube property sheet so that your users can see address details in their
OLAP report when they select any cell.
v Drill through to a cube having the same dimensions, but not all measures.
For example, a model based on an .iqd file has the measures Profit Margin,
Revenue, and Cost, and the drill-through report shows all three. You remove the
.imr report from the property sheet of the Profit Margin measure.
v Drill through to only those reports that are in scope, excluding all others based
on a set of restrictions established in the cube model.
Chapter 6. Creating PowerCubes
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