Information
The user-defined roles in Db2 can be nested in the same fashion as Windows security groups, i.e. a nested group has both its directly assigned permissions as well as the assigned group permissions. By nesting roles, the database administrator is saving time by only having to assign a group of users versus assigning them individually. Nesting roles properly can often ease the application of the security model if it's kept fairly shallow, and if the roles are logically named. If these are all true, then nesting of roles is a good idea.
Rationale:
As tracking multiple levels of permissions can result in unauthorized access to data resources, this capability should be restricted according to the needs of the business.
Solution
To remove a nested role, perform the following:
Connect to Db2 database:
db2 => connect to <dbname>
Run the following:
db2 => revoke role <role name> from role <role>