Synopsis

ALTER USER name [ [ WITH ] option [ ... ] ]

这里option可以是：
    
      SUPERUSER | NOSUPERUSER
    | CREATEDB | NOCREATEDB
    | CREATEROLE | NOCREATEROLE
    | CREATEUSER | NOCREATEUSER
    | INHERIT | NOINHERIT
    | LOGIN | NOLOGIN
    | CONNECTION LIMIT connlimit
    | [ ENCRYPTED | UNENCRYPTED ] PASSWORD 'password'
    | VALID UNTIL 'timestamp' 

ALTER USER name RENAME TO new_name

ALTER USER name SET configuration_parameter { TO | = } { value | DEFAULT }
ALTER USER name SET configuration_parameter FROM CURRENT
ALTER USER name RESET configuration_parameter
ALTER USER name RESET ALL