# Known Caveats

## Raw Queries

`django-treebeard` uses Django raw SQL queries for some write operations, and raw queries don’t update the objects in the ORM since it’s being bypassed.

Because of this, if you have a node in memory and plan to use it after a tree modification (adding/removing/moving nodes), you need to reload it.

## Overriding the default manager

One of the most common source of bug reports in `django-treebeard` is the overriding of the default managers in the subclasses.

`django-treebeard` relies on the default manager for correctness and internal maintenance. If you override the default manager, by overriding the `objects` member in your subclass, you WILL have errors and inconsistencies in your tree.

To avoid this problem, if you need to override the default manager, you’ll NEED to subclass the manager from the base manager class for the tree you are using.

Read the documentation in each tree type for details.

## Custom Managers

Related to the previous caveat, if you need to create custom managers, you NEED to subclass the manager from the base manager class for the tree you are using.

Read the documentation in each tree type for details.

## Copying model instances

Starting in version 4.5, we made a change to support custom names in primary fields that exposed a bug in Django’s documentation. This has been fixed in the dev version of Django (3.2 as of writing this), but even when using older versions, the new instructions apply.