I have used "immutable" schema designs when there were strong requirements for full audit needs over time. It works very well even in a normal RDBMs system. It also allows some very neat reporting e.g. compare the same report at different points in time.

The basic idea was that every operation (create, update, delete) are actually normal SQL inserts and all reads are against views defined such that the most recent tuples are returned unless they are flagged as "deleted."

I have typically used these types of designs in mostly simple applications with tables where the row counts are in the low millions of tuples. Dealing with this design in the billions of tuples (probably sharded somehow) might have motivated us out of normal RDBMs and into one of the specialized immutable DBs mentioned.