diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/ref/models/querysets.txt | 15 | ||||
| -rw-r--r-- | docs/releases/1.5.txt | 6 |
2 files changed, 21 insertions, 0 deletions
diff --git a/docs/ref/models/querysets.txt b/docs/ref/models/querysets.txt index 749a979db6..d17d869164 100644 --- a/docs/ref/models/querysets.txt +++ b/docs/ref/models/querysets.txt @@ -1667,6 +1667,21 @@ methods on your models. It does, however, emit the :data:`~django.db.models.signals.post_delete` signals for all deleted objects (including cascaded deletions). +.. versionadded:: 1.5 + Allow fast-path deletion of objects + +Django needs to fetch objects into memory to send signals and handle cascades. +However, if there are no cascades and no signals, then Django may take a +fast-path and delete objects without fetching into memory. For large +deletes this can result in significantly reduced memory usage. The amount of +executed queries can be reduced, too. + +ForeignKeys which are set to :attr:`~django.db.models.ForeignKey.on_delete` +DO_NOTHING do not prevent taking the fast-path in deletion. + +Note that the queries generated in object deletion is an implementation +detail subject to change. + .. _field-lookups: Field lookups diff --git a/docs/releases/1.5.txt b/docs/releases/1.5.txt index fddd03d421..5636a2b34b 100644 --- a/docs/releases/1.5.txt +++ b/docs/releases/1.5.txt @@ -149,6 +149,12 @@ Django 1.5 also includes several smaller improvements worth noting: * Django now provides a mod_wsgi :doc:`auth handler </howto/deployment/wsgi/apache-auth>` +* The :meth:`QuerySet.delete() <django.db.models.query.QuerySet.delete>` + and :meth:`Model.delete() <django.db.models.Model.delete()>` can now take + fast-path in some cases. The fast-path allows for less queries and less + objects fetched into memory. See :meth:`QuerySet.delete() + <django.db.models.query.QuerySet.delete>` for details. + Backwards incompatible changes in 1.5 ===================================== |