That's a good and complicated question. They both are fully ACID-compliant systems. The biggest difference as a developer is that Calvin never blocks reads, contested or not. You get causally consistent single-replica reads with no coordination.
This makes the read performance equivalent to something like Cassandra at CONSISTENCY.ONE, without giving up the cross-partition write linearization of something like Spanner.
Yes. This isn't near the top end, more like what happens when we run benchmarks on a reasonable web infrastructure class cluster. This is still only 5 machines in each datacenter.
How does this algorithm compare to whatever Google Spanner does?