Using Cognos
Transformer to Convert a Single Table (or Query) Source into a Data Cube
- Start
Transformer from the Start button menu
- Choose
File> New>
·
This will start up the New Model Wizard
- Click
“Next” button
- Type
in you model name (don’t include security for our work). Click “Next”
button
- Type
in a name for your source. Choose data source type from drop down (e.g.
Access Query or Access Table for our work). Click Next
- Click
the “Browse” button to find the database file. Find the file, then click
the “Open” button. (it appears that you need to have the DB be not
read-only, so you cannot directly use a DB on a CD-R)
- If the
“Table or Range” is not the one that you want, use the drop down to choose
the appropriate table or query. Click the “Next” button
- For
the most control, unclick the “Run AutoDesign” check box. Click the
“Finish” button.
- In the
“Data Sources” pane, click on the plus sign to show attributes
- Drag
measures (facts) into the Measures pane
- For
each dimension hierarchy:
·
Drag the highest level in the hierarchy (most summarized) to the gray
bar at the top of the “Dimension Map” pane (“dimension line”)
·
Drag other attributes in the hierarchy, in order from highest level of
summarization.
o
Dimensions hierarchies should be true hierarchies. Values for the lower
level should not be split among different values for the higher level.
o
This may mean that you are creating more than one hierarchy for a given
dimension. In Cognos, each of these will be considered a “dimension”. In some
cases the “hierarchy” may only be one level deep.
·
NOTE – the first two hierarchies are the ones
that will show up by default when the cube is opened. The order can be changed
by dragging the Dimension Line items around.
- Choose
File> Save>
- Specify
the file name and location (the type should be Model Files and the
filename extension .pyi – which should be the default)
- You
can double-click on the names on the dimension line to rename to more user
friendly names. You can do likewise for any other attributes in the
Dimension Map (change the “Level Name”)
- Choose
Run > Generate Categories>
- With
big data this will take some time
- If
warned about too many descendents, click ok. This is a user friendliness
issue (and possibly a performance issue). You might consider changing the
model if possible and re-running.
- When
you are ready to create a PowerCube (Cognos lingo for Data Cube), choose
Run > CreatePowerCubes
·
With big data, this will take some time
- To
view the cube created, choose Tools> PowerPlay > (though with a less
friendly interface than you are used to).
·
To save as a stand-alone file, from the viewed data, choose File >
Save As >, then specify name, location, and for type indicate PowerPlay Cube
(.mdc)
- The
result will be able to be opened on a computer with Cognos PowerPlay
installed. You will not be able to put them up on the WWW server since you
do not have access to it.
This is designed as a quick reference style tutorial. Data
Cubes can be created from multiple sources, can have alternative drill-down
paths and a time dimension can be automatically generated (I haven’t done these
yet). For more complete documentation, look under Start > All Programs
>Cognos > Documentation > PowerPlay > Discovering Transformer for a
pdf document.