help creating EM users and roles

Objective is to create grid control users who have limited access to specific database targets.  The users should not have sysoper or sysdba privs on the targets.  However, users will require ability to run advisors under the "advisor central" link (sql tuning advisor, segment advisor, access advisor, etc).  Am having trouble tracking down specifically which privileges the db user will require to use these advisors.

Attempts so far have resulted in the following error when clicking on the "advisor central" link, because I do not know specifically which privileges the db schema must have:   "Database Error: The application requires more database privileges than you have currently been granted. Click on Help to get more version specific information."  Again, I do not wish to give sysoper or sysdba privs.