Setting up Multiple Databases on a current site 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?
I think I figured out what to do in order to pull this off. The issue was that the documentation in default.settings.php was rather lacking but I managed to piece it together. You do have to set your tables up explicitly and your databases as well. It has not helped the issue at all, and frankly it concerns me due to the issues with Drupal 8 coming that frankly might not be usable. So I'm going to pursue a different course of action on this.