You can use IBM®
Cognos® Framework Manager to detect and generate
relationships between two or more existing objects in your model. This is useful when you import
metadata in stages, or when you want to change the criteria that apply to existing relationships,
such as whether they include outer joins.
When importing star schema metadata, avoid generating relationships based on matching column or
query item names unless you have naming conventions in place. Data warehouses often apply naming
standards to columns, such as surr_key as the default column name for surrogate
keys in dimensions. In this case, generating relationships that are based on matching column names
generates inappropriate relationships between all dimension tables.
Procedure
- Ctrl+click two or more objects.
- Click Tools, Detect Relationships.
- Select the rules you want to apply to each pair of tables.
|
Rule
|
Result
|
|
Use primary and foreign keys
|
Creates joins that are based on primary key and foreign key relationships. The query item names
do not have to match.
|
|
Use matching query item names that represent uniquely indexed columns
|
Creates joins between query items whose names and data types match, if one or both of the
underlying columns are uniquely indexed.
|
|
Use matching query item names
|
Creates joins between query items whose names and data types match. This generates as many
relationships as possible.
|
- Indicate whether you want Framework Manager to detect and generate relationships between
- The selected objects
- Each selected object and every object in the project that is not selected
- The selected objects and every other object in the project
- Identify whether you want Framework Manager to create outer joins or inner joins based on
outer joins that exist in the data source.
- If you want to disable the automatic prevention of double-counting, convert all
n cardinalities to 1 by clearing the Fact detection
enabled check box.
- Click OK.