Mirgration 0008_alter_attachment_file_attachment_and_more.py fails with Oracle Backend

[badeendjuh]

Application of the index on mailqueue.MailerMessage.to_address generates a django warning:
mailqueue.MailerMessage.to_address: (fields.W162) Oracle does not support a database index on NCLOB columns.

and applying the migration fails with:
oracledb.exceptions.DatabaseError: ORA-02327: cannot create index on expression with datatype LOB

System check identified some issues:

WARNINGS:
mailqueue.MailerMessage.to_address: (fields.W162) Oracle does not support a database index on NCLOB columns.
	HINT: An index won't be created. Silence this warning if you don't care about it.
Operations to perform:
  Apply all migrations: mailqueue
Running migrations:
  Applying mailqueue.0008_alter_attachment_file_attachment_and_more...Traceback (most recent call last):
  File "/venv/lib/python3.12/site-packages/django/db/backends/utils.py", line 105, in _execute
    return self.cursor.execute(sql, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/django/db/backends/oracle/base.py", line 577, in execute
    return self.cursor.execute(query, self._param_generator(params))
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib64/python3.12/site-packages/oracledb/cursor.py", line 710, in execute
    impl.execute(self)
  File "src/oracledb/impl/thin/cursor.pyx", line 196, in oracledb.thin_impl.ThinCursorImpl.execute
  File "src/oracledb/impl/thin/protocol.pyx", line 439, in oracledb.thin_impl.Protocol._process_single_message
  File "src/oracledb/impl/thin/protocol.pyx", line 440, in oracledb.thin_impl.Protocol._process_single_message
  File "src/oracledb/impl/thin/protocol.pyx", line 432, in oracledb.thin_impl.Protocol._process_message
  File "src/oracledb/impl/thin/messages.pyx", line 74, in oracledb.thin_impl.Message._check_and_raise_exception
oracledb.exceptions.DatabaseError: ORA-02327: cannot create index on expression with datatype LOB
Help: https://docs.oracle.com/error-help/db/ora-02327/

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/opt/exaboard/source/exaboard/django/manage.py", line 21, in <module>
    main()
  File "/opt/exaboard/source/exaboard/django/manage.py", line 17, in main
    execute_from_command_line(sys.argv)
  File "/venv/lib/python3.12/site-packages/django/core/management/__init__.py", line 442, in execute_from_command_line
    utility.execute()
  File "/venv/lib/python3.12/site-packages/django/core/management/__init__.py", line 436, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/venv/lib/python3.12/site-packages/django/core/management/base.py", line 413, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/venv/lib/python3.12/site-packages/django/core/management/base.py", line 459, in execute
    output = self.handle(*args, **options)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/django/core/management/base.py", line 107, in wrapper
    res = handle_func(*args, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/django/core/management/commands/migrate.py", line 357, in handle
    post_migrate_state = executor.migrate(
                         ^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/django/db/migrations/executor.py", line 135, in migrate
    state = self._migrate_all_forwards(
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/django/db/migrations/executor.py", line 167, in _migrate_all_forwards
    state = self.apply_migration(
            ^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/django/db/migrations/executor.py", line 255, in apply_migration
    state = migration.apply(state, schema_editor)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/django/db/migrations/migration.py", line 132, in apply
    operation.database_forwards(
  File "/venv/lib/python3.12/site-packages/django/db/migrations/operations/fields.py", line 241, in database_forwards
    schema_editor.alter_field(from_model, from_field, to_field)
  File "/venv/lib/python3.12/site-packages/django/db/backends/oracle/schema.py", line 75, in alter_field
    super().alter_field(model, old_field, new_field, strict)
  File "/venv/lib/python3.12/site-packages/django/db/backends/base/schema.py", line 905, in alter_field
    self._alter_field(
  File "/venv/lib/python3.12/site-packages/django/db/backends/base/schema.py", line 1220, in _alter_field
    self.execute(self._create_index_sql(model, fields=[new_field]))
  File "/venv/lib/python3.12/site-packages/django/db/backends/base/schema.py", line 202, in execute
    cursor.execute(sql, params)
  File "/venv/lib/python3.12/site-packages/django/db/backends/utils.py", line 122, in execute
    return super().execute(sql, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/django/db/backends/utils.py", line 79, in execute
    return self._execute_with_wrappers(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/django/db/backends/utils.py", line 92, in _execute_with_wrappers
    return executor(sql, params, many, context)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/django/db/backends/utils.py", line 100, in _execute
    with self.db.wrap_database_errors:
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/django/db/utils.py", line 91, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/venv/lib/python3.12/site-packages/django/db/backends/utils.py", line 105, in _execute
    return self.cursor.execute(sql, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib/python3.12/site-packages/django/db/backends/oracle/base.py", line 577, in execute
    return self.cursor.execute(query, self._param_generator(params))
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/venv/lib64/python3.12/site-packages/oracledb/cursor.py", line 710, in execute
    impl.execute(self)
  File "src/oracledb/impl/thin/cursor.pyx", line 196, in oracledb.thin_impl.ThinCursorImpl.execute
  File "src/oracledb/impl/thin/protocol.pyx", line 439, in oracledb.thin_impl.Protocol._process_single_message
  File "src/oracledb/impl/thin/protocol.pyx", line 440, in oracledb.thin_impl.Protocol._process_single_message
  File "src/oracledb/impl/thin/protocol.pyx", line 432, in oracledb.thin_impl.Protocol._process_message
  File "src/oracledb/impl/thin/messages.pyx", line 74, in oracledb.thin_impl.Message._check_and_raise_exception
django.db.utils.DatabaseError: ORA-02327: cannot create index on expression with datatype LOB
Help: https://docs.oracle.com/error-help/db/ora-02327/