users_and_permissions_psql.sql

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 role_attributes
FROM pg_catalog.pg_user
ORDER BY role_name desc;