id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
20863	Clarify which session backends require django.contrib.sessions in INSTALLED_APPS	Keryn Knight <django@…>	nobody	"Between #20444 and #20418, the [https://docs.djangoproject.com/en/dev/topics/http/sessions/#using-cookie-based-sessions cookie based sessions] now includes useful notes explaining how cookies differ, and specifically, there is a note which reads:

''When using cookies-based sessions `django.contrib.sessions` can be removed from `INSTALLED_APPS` setting because data is loaded from the key itself and not from the database, so there is no need for the creation and usage of `django.contrib.sessions.models.Session` table.''

In light of that explanation, it's not clear why it is singled out as the only one that can remove `django.contrib.sessions` from the INSTALLED_APPS. Can any of the others? The answer is, according to the documentation ... unclear; there is a paragraph at the end of the [https://docs.djangoproject.com/en/dev/topics/http/sessions/#using-cached-sessions cached sessions docs] which suggests using `cached_db` requires following the [https://docs.djangoproject.com/en/dev/topics/http/sessions/#using-database-backed-sessions database sessions setup], which involves having `django.contrib.sessions` installed. So by implication, using the **cached** backend (rather than the **cached_db**) shouldn't require following the same setup requirements. The **file** based caching gets such a cursory mention, it could go either way.

As part of the ticket, I think the highlighted point about the cached_db requirements ought to be a Sphinx `.. note::`, as it is only in reading & re-reading these docs to draft this ticket that I noticed it."	Cleanup/optimization	closed	Documentation	dev	Normal	wontfix			Accepted	0	0	0	0	0	0