Member Unique Names

In the IBM® Cognos® studios, the Member Unique Name (MUN) is the unique identifier for locating the category or member in the data source. The MUN is much like the business key in a table.

Cognos metadata uses the Cognos Transformer model category codes when defining the MUN of a PowerCube category or member.

Member Unique Names are used

  • as data item references for categories or members in any report specification
  • as the value passed in PowerCube to PowerCube drill through in any report
  • as identifiers for categories or members used in filters, expressions, parameters, or calculations in IBM Cognos Analytics
  • to return categories or members to IBM Cognos applications

    Any time a Cognos application requests the category or member, the MUN ensures that the unique category or member is returned.

Tip: You can view the Member Unique Name for a category or member in Reporting. In Reporting, open a PowerCube package, select a category, and view the category properties.

Each time a PowerCube category code changes, the MUN reflects the change. When categories or members are directly referenced in expressions, filters, or reports, and the MUN changes, the category or member is no longer found. This is because the original MUN is contained in the report specification.

Member Unique Names can change for different reasons:

  • Changes in the hierarchy and level structures can result in changes to MUNs.
  • Relative time categories may change, for example, when the current quarter moves from one to the next.
  • If a source value changes, the category code used in the MUN also changes, unless the category code is specifically set to use a unique data item in the model design.
  • The production environment may have more categories or members than the test environment.
  • The category or member may no longer exist in the data source.

To avoid these problems, use the following best practices:

  • Use unique codes and keys within a dimension for the category or member keys.

    Ensure that your Cognos Transformer model source values have unique values throughout the levels of each dimension. This ensures that the model category codes, and therefore the MUNs, are more stable.

  • Use unique conformed source values for similar dimensions between the target and source environments when enabling drill through.
  • Ensure that the business keys and dimension metadata structure are the same between the production and test environments.
  • If the data source is a package or report, do not change the business keys after going into production.
  • Resolve the non-unique keys within a dimension in the data source.

    Do not use the tilde character (~) in the category codes because this might produce unstable MUN values.

  • If you have tildes within your category codes, do not use the Clean House feature.

    Using the Clean House feature will most likely change the category codes.

  • Keep a backup of your .mdl file and revert to the backup .mdl model file if the current model file becomes corrupt and requires a Clean House action.