I'm having issues with my current shared hosting provider due to my core database exploding upwards of 1GB due to cache_form. I've been looking at trying to offload the cache and revisions databases into different databases entirely and set them away in order to hold down the load. I think my understanding of how is ok but I want to be sure as this is a current live site.
I declare the default database then declare where each table is explicitly in the prefix array. If this is accurate then I will just do it that way, if not then I'd like to know where I'm going wrong. Do I need to explicitly declare ALL my databases first in settings.php or do I need to declare just my default and let it work that way?