I can only speculate, because I have never used datomic.

Like FoundationDB, datomic does appear to separate transaction processing from storage.

A few relevant differences:

- Datomic provides transaction isolation through stored procedures which run on its single "transactor", while FoundationDB provides interactive transactions.

- To my knowledge datomic does not claim to be interested in high write scalability, which we definitely are.

- Datomic is designed to keep multiversion history indefinitely, while FoundationDB keeps it just long enough to execute short transactions.