[PixyMisa]

Or ZFS snapshots, for example.

From the description it looks like it would be easy to do backups, it's just that mysqldump is not currently aware of temporal tables.

Just use

SELECT * FROM t FOR SYSTEM_TIME ALL;

And export it in an appropriate format.

[crazygringo]

That does, of course, export complete data, but the problem is you can't then import it, because that breaks the entire guarantee about not being able to edit past data.

[PixyMisa]

Ah. There is that.

They really need to create a workaround for that, because sooner or later you will need to migrate your data and right now it's simply impossible.

Edit: Particularly as, reading further, you cannot ALTER a temporal table. Which does make sense, but the problem remains.