This is true but it’s nice to have the whole app, data and database in one place, going together, snapahotted together, backupable together. It’s slower for sure. With a large pool (more disks) and especially with the magic of SSD cache, database reads fly and reads are the majority of the loads in my heads. In the future I would put root on ZFS as well and either do SSD cache or have root on ZFS SSD pool that gets send/recved regularly onto the spinning pool so it’s easy to restore when needed.