Member Unique Names

The member unique name (MUN) is a unique identifier for a member in IBM® Cognos® reports. It is stored in the report specification when the member is referenced in the report directly.

The MUN is used in drill-through between OLAP data sources. The member keys in the MUN for the different OLAP data sources must match.

The MUN is used to find the member in the data source, which is similar to how business keys are used to find records in a table. For example, when you create OLAP dimension Products, you use the Product Line database column as s label for the members in your Product Line level. However, you use the Product Line Code business key from the database table to ensure that all the Product lines are unique in that level. The source value that you used to create the members is used in combination with the data source name, hierarchy, and level information in the member unique name.

If the MUN changes, members that are directly referenced in expressions, filters, or reports are no longer found. Changes to the MUN may be related to other changes. For example, changes to the hierarchy and level structures may change the level unique name, and changes to the business key values may change the member key path. Other factors that can affect the MUN are application changes during the design stage or over time, IBM Cognos PowerCube category codes that are unpredictably unique, the production environment that has more members than the test environment, or removing the member from the data source.

To avoid potential problems, we recommend the following best practices when you build OLAP data sources:

Use unique codes and keys within a dimension for the member keys.
Define your OLAP and relational packages using unique conformed values for the source values (business keys) within similar dimensions or data values where drill-through between applications may be required.
Ensure that the business keys and dimension metadata structure are the same in the production and test environments.
Do not change the business keys in IBM Cognos Framework Manager in the production environment.
Resolve the non-unique keys in a dimension in the data source before you build the cube.
Ensure that there are no duplicate source values in all levels of a dimension before you build a PowerCube. We do not recommend using the tilde character (~) in the category codes.

For more information, see the section about uniqueness in the IBM Cognos Series 7 Step-by-Step Transformer.

For information about PowerCubes migrated from IBM Cognos Series 7, see the IBM Cognos PowerPlay® Migration and Administration Guide.