[drupal-devel] filter cache one day expire design rationale?

[Dries Buytaert]

On 12 May 2005, at 11:29, Karoly Negyesi wrote:
> Why check_output caches for one day instead of cache_permanent?

If someone edits a node (or any piece of filtered content), the "old 
filtered body" is not automatically pruned from the cache.  Instead, 
the "new filtered body" is added and the "old filtered body" is removed 
within 24 hours.
Similarly, if a node (or any piece of filtered content) is removed from 
the site, its "filtered body" won't be automatically removed from the 
cache.  Instead, we take the "lazy yet aggressive yet error-prone 
approach" and wipe all filtered text every once in a while.  In 
addition, it ensures that we don't keep stale content in the cache 
which keeps the cache table ... *cough* ... small.

(I see a quite a lot of filter cache updates on drupal.org though.)

--
Dries Buytaert  ::  http://www.buytaert.net/