用于psql -U postgres登录。

postgres=> CREATE DATABASE mydb;
postgres=> \c mydb;

You are now connected to database "mydb" as user "postgres".

创建模式时，得到

mydb=> CREATE SCHEMA main;
ERROR:  permission denied for database mydb

没有设置的可能被拒绝的权限是什么？

编辑

当我跑步时\l，它显示

   Name    |        Owner         | Encoding |   Collate   |    Ctype    |               Access privileges
-----------+----------------------+----------+-------------+-------------+-----------------------------------------------
 mydb      | mydb_administrator   | UTF8     | en_US.UTF-8 | en_US.UTF-8 | =Tc/mydb_administrator                     +
           |                      |          |             |             | mydb_administrator=CTc/mydb_administrator
 postgres  | postgres             | UTF8     | en_US.UTF-8 | en_US.UTF-8 |
 ...

\du得到

      Role name       |                         Attributes                         |                          Member of
----------------------+------------------------------------------------------------+-------------------------------------------------------------
 mydb_administrator   |                                                            | {rds_iam}
 mydb_application     | Cannot login                                               | {}
 mydb_user            |                                                            | {rds_iam,mydb_application}
 postgres             | Create role, Create DB                                    +| {rds_superuser}
                      | Password valid until infinity                              |
 ...

所有的事情都是由postgres用户执行的。