SELECT usename AS role_name,
       CASE
           WHEN usesuper AND usecreatedb THEN
               cast('superuser, create database' AS pg_catalog.text)
           WHEN usesuper THEN
               cast('superuser' AS pg_catalog.text)
           WHEN usecreatedb THEN
               cast('create database' AS pg_catalog.text)
           ELSE
               cast('' AS pg_catalog.text)
       END     AS role_attributes
FROM pg_catalog.pg_user
ORDER BY role_name DESC;