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
24035	Poor/incorrect documentation for CACHE_MIDDLEWARE_KEY_PREFIX in relation to CACHES[alias]['KEY_PREFIX']	Frankie Robertson	Frankie Robertson	"The interaction between CACHES[alias]['KEY_PREFIX'], CACHE_MIDDLEWARE_KEY_PREFIX and @cache_page(... key_prefix) is poorly documented. It should be made explicit that KEY_PREFIX is always used and combined with CACHE_MIDDLEWARE_KEY_PREFIX or @cache_page(... key_prefix)

Changes should be made to both ref/settings and topics/cache.

The paragraph at the bottom of https://docs.djangoproject.com/en/dev/topics/cache/#the-per-view-cache is particularly troublesome:

""The two settings can also be combined. If you specify a cache and a key_prefix, you will get all the settings of the requested cache alias, but with the key_prefix overridden.

Having looked through the source it appears as though the setting CACHE_MIDDLEWARE_KEY_PREFIX OR the argument to @cache_page is combined with the rest of the cache key using django.utils.cache.get_cache_key which is then combined with the CACHES[alias]['KEY_PREFIX'] using key_func."	Bug	new	Documentation	dev	Normal				Unreviewed	0	0	0	0	0	0