That was the point of Citrine (a single cache for all apps), but it never really panned out. We realized each app needs different things, and if everybody just put everything into one db that db becomes way too large (60GB) that is impossible to manage.

We need to figure out a way that apps can tell this central database to delete stuff that they are not using anymore. Which means that the DB needs to track which information is useful for which app and that alone might make the DB even larger.

Hard problems to solve.

On Amethyst, it all depends if the app is getting killed all the time or not. If it stays in memory, the use of data is not that big.