To help keep world sizes small you could try to do it like how ECO does it.

[link12313]

It also uses a database to store it's voxels. But it has a system known as sleeping chunks where if a chunk remains unedited for a long time it will compress it to save space. It uses its own claim system to control what chunks are asleep and active. And it's world passively change somewhat like vintage stories. https://play.eco/