CHANGELOG.rst

0.5.6 (2023-07-09)

• Adds a model validation in addition to the existing database error, when users try to make a cycle (mark a node as its own parent or ancestor)
• Moves PathField.get_roots() to TreeQuerySetMixin.filter_roots().
• Fixes a TypeError when using TreeQuerySetMixin.get_descendants() on an empty queryset.

0.5.5 (2023-07-06)

Fixes another PostgreSQL 12 compatibility issue.

0.5.4 (2023-07-06)

Fixes an SQL syntax error.

0.5.3 (2023-07-06)

Fixes a PostgreSQL implicit type casting that was not done in PostgreSQL 12.

0.5.2 (2023-07-06)

Fixes a source of path clashes when the objects have exactly the same values for all order_by columns.

0.5.1 (2023-07-06)

Big rewrite using arrays of decimals instead of strings to represent the path.

Performance

For more details, see the benchmark results.

• Inserting becomes orders of magnitude faster, often faster than django-treebeard and django-mptt.
• Updating becomes faster in all cases, especially when the instance stays at the same place where it becomes orders of magnitude faster.
• Deleting becomes most of the time orders of magnitude faster.
• Reading stays as fast as it was.

Upgrading

• Add a new empty migration in each application that contains PathFields.
• For each PathField defined in the application, add:
  • DeleteTreeTrigger
  • RemoveField of the path field
  • AddField of the path field
  • CreateTreeTrigger
  • RebuildPaths

For example:

DeleteTreeTrigger('Place'),
migrations.RemoveField('Place', 'path'),
migrations.AddField(
    model_name='Place',
    name='path',
    field=PathField(db_index=True, order_by=['name'], size=None),
),
CreateTreeTrigger('place'),
RebuildPaths('place'),

You can also comment the PathField in the model itself, run makemigrations to create a first migration with the RemoveField, add the DeleteTreeTrigger before, then uncomment the field in the model, run makemigrations to generate a second migration with the AddField in it, and finally add the CreateTreeTrigger and RebuildPaths at the end.