[support] When are Caches Cleared?

[Earnie Boyd]

Fred Jones wrote:
>
> Question is when does it expire? I see there is a minimum and mine is
> set to NONE. I *think* what I am asking is about the maximum.

That would depend on the "cache_flush_$table" variable and the 
cache_lifetime variable and whether or not the cache is deemed 
CACHE_PERMANENT (a.k.a. expire == 0).  See 
http://api.drupal.org/api/function/cache_get/6 for more information. 
CACHE_PERMANENT should only be used for things like variables data and 
the theme_registry.  'cache_lifetime' is the variable for the minimum.

Tracing through it, maybe there is a bug but I don't know it to be.  I 
am sure that if "cache_flush_$table" isn't set that the cache will never 
be deleted unless cache_clear_all is called with a "wildcard".

-- 
Earnie
-- http://progw.com
-- http://www.for-my-kids.com