How to cache a collection in Magento?

Question

I have a collection that takes significant time to load. What I would like is to cache it (APC, Memcache). It is not possible to cache the entire object (as it cannot be unserialized and it is over 1 MB). I'm thinking that caching the collection data ($col->getData() ) is the way to go, but I found no way to rebuild the object based on this array. Any clues?

Answer 1

I really don't know, but I searched for all the files that have the word "cache" in them with file names of "Collection.php" and got a few results. The most promising example to look at might be Mage_Sales_Model_Entity_Quote_Item_Collection (_getProductCollection() method). Looks like Varien_Data_Collection (which is a parent class of any magento collection) has a few cache-related methods: initCache() and _getCacheInstance().

Can't say I have used them before but might be useful someday.

Good luck.