alter_user_statement 

<alter_user_statement> ::=
  ALTER USER <user_name> [<user_mode>]
    [TIMEOUT <unsigned_integer> | TIMEOUT NULL]
    [COSTWARNING <unsigned_integer> | COSTWARNING NULL]
    [COSTLIMIT <unsigned_integer> | COSTLIMIT NULL]
    [DEFAULT ROLE ALL [EXCEPT <role_name>] | DEFAULT ROLE NONE | DEFAULT ROLE <role_name>]
    [[NOT] EXCLUSIVE]
    [DEFAULTCODE ASCII]
    [DEFAULTCODE UNICODE]
    [<connect_mode>]