1. A role is created using the CREATE ROLE statement. This role is initially empty. Only database users belonging to database user class DBA are able to create roles . The new role name cannot be the same as the name of any other role, a user, or a user group.
3. A role can be assigned to database users, user groups, or other roles using the GRANT statement and specification of the role name.
database session, you can use the SET statement to activate other roles
assigned to the user or user group
If a role is activated during a session, the current user then has all the privileges that are assigned to a role.
If a password has been assigned to a role, users assigned to that role can only activate it by entering the password in the SET statement.
That a role is available and the properties of that role are all registered in the catalog in the form of metadata. A user that creates a role becomes its owner.
The roles assigned to the user or user group as a result of the ALTER USER and ALTER-USERGROUP statements are activated as soon as a database session is opened.
Roles are not active during execution of data definition commands.
Reference Manual: SAP DB 7.4, Section Role Name