Syncing data is an easier problem than what the parent is trying to solve. RSync is one such solution. If you want to run compute over big data, you replicate

Syncing data is an easier problem than what the parent is trying to solve. RSync is one such solution. If you want to run compute over big data, you replicate the database with a server you own and run compute on a copy of the data. Realistically that is what Amazon would have to do for you either way - they'd be running replicas you could compute over. And those replicas need to say in sync via db replication. Secure competition over anonymized datasets is useful for security reasons, not efficiency reasons IMHO.