Oracle EM 11G – Fixing Backup Settings Changes Not Sticking

One of the key differences between these platforms is that a database in MySQL is a schema in Oracle. Since a schema in Oracle is also a user, the command you are looking for is CREATE USER. I highly recommend that you read the Oracle Concepts Guide before continuing. You may also find this documentation on MySQL>>Oracle migrations using SQL Developer useful. Here is the part relevant to your situation:

When migrating MySQL databases to Oracle, SQL Developer maps each MySQL database to a tablespace in Oracle. Database objects, such as tables, indexes and views are stored in the respective tablespaces and are referenced from the Oracle schema for the user that owns them.

From the error message perspective, the salient part to pull out is "ORA-01100: database already mounted". This indicates that a database has already been created and mounted. It may also be open. Here is an example reproducing your issue, opening the database (which may not be necessary if it is already open) and creating a django user.

SQL> create database django;
create database django
*
ERROR at line 1:
ORA-01501: CREATE DATABASE failed
ORA-01100: database already mounted


SQL> SELECT status FROM v$instance;

STATUS
------------
MOUNTED

SQL> ALTER DATABASE OPEN;

Database altered.

SQL> SELECT status FROM v$instance;

STATUS
------------
OPEN

SQL> create database django;
create database django
*
ERROR at line 1:
ORA-01501: CREATE DATABASE failed
ORA-01100: database already mounted


SQL> CREATE USER django IDENTIFIED BY "No More ORA-001100.";

User created.

You should also assign permissions and create a django tablespace setting it as the default tablespace for django.

The "device" in RMAN is a misnomer, it should be really called "storage".

The "sbt" (synonym of "sbt_tape") is a misnomer again, as it has NOTHING to do with any tapes, it should be simply called "non-rman". This is just an empty placeholder, to be filled with any "plugin"; the plugin is called by Oracle either the "Media Manager library" or SBT_LIBRARY. This plugin allows rman to store and retrieve files through it, so rman only tells that it needs a file handle "xyz" (file is identified by a string handle) and doesn't need to know how the file is delivered, from tape or anything. The plugin is normally a part of an independent backup software, such as IBM TSM or Symantec NetBackup or many others. Oracle provides a simple emulator SBT_LIBRARY=oracle.disksbt for testing.

Since you didn't fill that placeholder with any "Media Manager library", you receive an error message as expected.