Viewing roles and their privileges

You can view predefined roles and their privileges in your RDS for PostgreSQL DB instance using different commands depending on your PostgreSQL version. To see all predefined roles, you can connect to your RDS for PostgreSQL DB instance and run following commands using the psql.

For psql 15 and earlier versions

Connect to your RDS for PostgreSQL DB instance and use the \du command in psql:

postgres=> \du
                                                               List of roles
    Role name    |                         Attributes                         |                          Member of
-----------------+------------------------------------------------------------+------------------------------------------------------
 postgres        | Create role, Create DB                                    +| {rds_superuser}
                 | Password valid until infinity                              |
 rds_ad          | Cannot login                                               | {}
 rds_iam         | Cannot login                                               | {}
 rds_password    | Cannot login                                               | {}
 rds_replication | Cannot login                                               | {}
 rds_superuser   | Cannot login                                               | {pg_monitor,pg_signal_backend,rds_password,rds_replication}
 rdsadmin        | Superuser, Create role, Create DB, Replication, Bypass RLS+| {}
                 | Password valid until infinity                              |

For psql 16 and later versions

postgres=> \drg+
                             List of role grants
   Role name   |          Member of          |       Options       | Grantor
---------------+-----------------------------+---------------------+----------
 postgres      | rds_superuser               | INHERIT, SET        | rdsadmin
 rds_superuser | pg_checkpoint               | ADMIN, INHERIT, SET | rdsadmin
 rds_superuser | pg_monitor                  | ADMIN, INHERIT, SET | rdsadmin
 rds_superuser | pg_signal_backend           | ADMIN, INHERIT, SET | rdsadmin
 rds_superuser | pg_use_reserved_connections | ADMIN, INHERIT, SET | rdsadmin
 rds_superuser | rds_password                | ADMIN, INHERIT, SET | rdsadmin
 rds_superuser | rds_replication             | ADMIN, INHERIT, SET | rdsadmin

To check role membership without version dependency, you can use the following SQL query:

SELECT m.rolname AS "Role name", r.rolname AS "Member of"
FROM pg_catalog.pg_roles m
JOIN pg_catalog.pg_auth_members pam ON (pam.member = m.oid)
LEFT JOIN pg_catalog.pg_roles r ON (pam.roleid = r.oid)
LEFT JOIN pg_catalog.pg_roles g ON (pam.grantor = g.oid)
WHERE m.rolname !~ '^pg_'
ORDER BY 1, 2;

In the output, you can see that rds_superuser isn't a database user role (it can't login), but it has the privileges of many other roles. You can also see that database user postgres is a member of the rds_superuser role. As mentioned previously, postgres is the default value in the Amazon RDS console's Create database page. If you chose another name, that name is shown in the list of roles instead.