YugabyteDB是否支持Django，尽管目前还不支持SAVEPOINTS功能？

Question

设置Django应用程序与YugabyteDB对话，但在运行迁移时遇到以下错误：

Traceback (most recent call last):
  File "/opt/env/lib/python3.6/site-packages/django/contrib/contenttypes/models.py", line 54, in get_for_model
    ct = self.get(app_label=opts.app_label, model=opts.model_name)
  File "/opt/env/lib/python3.6/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/opt/env/lib/python3.6/site-packages/django/db/models/query.py", line 380, in get
    self.model._meta.object_name
__fake__.DoesNotExist: ContentType matching query does not exist.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/env/lib/python3.6/site-packages/django/db/models/query.py", line 464, in get_or_create
    return self.get(**lookup), False
  File "/opt/env/lib/python3.6/site-packages/django/db/models/query.py", line 380, in get
    self.model._meta.object_name
__fake__.DoesNotExist: ContentType matching query does not exist.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/env/lib/python3.6/site-packages/django/db/backends/utils.py", line 62, in execute
    return self.cursor.execute(sql)
  File "/opt/env/lib/python3.6/site-packages/django_prometheus/db/common.py", line 63, in execute
    return super(CursorWrapper, self).execute(*args, **kwargs)
psycopg2.errors.FeatureNotSupported: SAVEPOINT <transaction> not supported yet
LINE 1: SAVEPOINT "s140500455238528_x1"
        ^
HINT:  See https://github.com/YugaByte/yugabyte-db/issues/1125. Click '+' on the description to raise its priority

既然YugabyteDB目前似乎不支持SAVEPOINTS，那么我们如何避免这个Django错误呢？

免责声明:这个问题最初是由一位YugabyteDB用户通过电子邮件提出的

Answer 1

YugabyteDB将在较新的版本中支持Savepoint feature。所以这个问题可能看不到。

但是，我们已经构建了一个Django backend for YugabyteDB。它保证了YugabyteDB与Django的兼容性。在新版本进入生产环境之前，我们已经禁用了后端的保存点支持，即后端告诉Django它不支持保存点(uses_savepoints = False)，因此Django不会自动使用保存点，应该不会看到这个异常。但是，最外层事务的原子性仍然是有保证的。

此外，不应该显式地使用savepoint API，因为它将是无操作的，除非您使用的是支持savepoint的YB版本。