pg_auth_members
   The catalog pg_auth_members shows the membership
   relations between roles.  Any non-circular set of relationships is allowed.
  
   Because user identities are cluster-wide,
   pg_auth_members
   is shared across all databases of a cluster: there is only one
   copy of pg_auth_members per cluster, not
   one per database.
  
Table 53.9. pg_auth_members Columns
| Column Type Description | 
|---|
| 
        ID of a role that has a member | 
| 
        
       ID of a role that is a member of  | 
| 
        ID of the role that granted this membership | 
| 
        
       True if  |