I tend to think of the database less as a filesystem and more as a block store. The filesystem layer in a real system is in fact implemented by the driver (and

I tend to think of the database less as a filesystem and more as a block store. The filesystem layer in a real system is in fact implemented by the driver (and OS), and it might be implemented in terms of primitives that are persisted in the block device, but the block device doesn’t have a magical internal scripting language or query engine that the driver delegates to. The driver is in charge, and the persistence layer stores and loads what the driver tells it to.