It's just a personal reflexion, maybe some topics already exists on it, so excuse me by advance if I'm completely out of context.
I was reading the latest release notes and see the fix regarding persistent caching for Mysql.
Good news but regarding the number of databases supported by Metabase it will be a long journey to support everything.
Plus, I'm not fan to plug an analytics system with anything else than reader rights. I always prefer to follow a separation of concern pattern, and even if the actual persistent caching is maybe done to ease such setup, I think we can achieve something equivalent but in a more efficient manner.
So why not supporting a universal persistent caching to a dedicated database connection? More than what was described before, using a database optimized for caching (like Redis) can also improve the cache performance as well as the plugged analytic databases (less pressure related to cache schema usage).
on the first post