Create A Cube Group; Defining A Time-Based Partitioned Cube - IBM Cognos User Manual

Create a Cube Group

You can create a cube group for any level in a dimension and add child cubes that
include selected categories or measures. For each cube in a group, you must
specify the degree of detail to be included so that your users see only the most
relevant data.
For example, suppose you work for a national chain of travel agencies that uses
one data source and one model to generate its sales reports. You create one large
cube that can be accessed by several different user groups and roles, and a set of
smaller cubes that are each accessed by only one user group. Senior managers see
total and regional sales figures for each travel product. Regional managers see
figures for only their regions.
Although it takes longer to build several smaller cubes, managers will see faster
query response times, and each regional cube contains data relevant to only that
regional manager.
Procedure
1. Click in the PowerCubes list to make it active and, from the Edit menu, click
2. In the PowerCube name box, type a name for the new PowerCube group.
3. Click the Cube Group tab.
4. In the Dimension box, select the dimension from which you want to build the
5. In the Level box, select the level whose categories will become the individual
6. In the Focus of detail area, select the lowest level of category detail.
7. When you have finished setting the required properties on each of the other

Defining a Time-based Partitioned Cube

Time-based partitioning is a useful means of optimizing cubes for OLAP reporting
purposes. Time-based partitioned cubes are a collection of child cubes, based on
one level in the time dimension, that together form one large cube. Each child cube
is partitioned, or split, at the appropriate reporting level, such as Quarter or
Month.
Report users can view each cube independently, or access the entire collection of
child cubes as a single, time-based virtual cube. This means that reports can be
viewed across the entire time dimension, or across only one level in the time
dimension, such as a specific month.
Cognos Transformer creates and maintains two separate files to manage the
time-based cube group. The first is a time-based control file (.vcd), which is an
editable ASCII-format text file that references the cubes that make up the
time-based group and their physical locations. The second file is a control cube
(.mdc), which:
v contains the high-level metadata about the overall structure of the cubes
Insert PowerCube.
cube group.
cubes in the cube group.
Note: This is the level at which you want data for external categories to be
summarized.
tabs in the PowerCube property sheet, click OK.
Chapter 6. Creating PowerCubes
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