You can change the user's name with ALTER USER.
※This sample exam is different from those that appear in the actual OSS-DB Exam.
2019/05/21
Creating, deleting and changing database users are done using the CREATE USER, DROP USER, and ALTER USER statements, respectively. In PostgreSQL implementation, users and roles are not different, so CREATE ROLE, DROP ROLE, ALTER ROLE can do the same thing.
CREATEROLE authority is required to create, delete and change users. Of course, even an administrator user with SUPERUSER privilege can perform the same operation, but there is no authority called DROPROLE. There is also authority called CREATEUSER, but since it is deprecated and it has the same meaning as SUPERUSER, please be careful.
PostgreSQL does not automatically create a schema even if CREATE USER is executed. If necessary, CREATE SCHEMA is used.
When deleting a user with DROP USER, an error occurs if the user owns an object such as a table. You must delete the object owned by the user before you can delete the user.
ALTER USER old_name RENAME TO new_name;
You can change the name of an existing user by executing it.
Therefore, the correct answers are B and E.
You can change the user's name with ALTER USER.