  Private blockchain as a replicated transactional system shares many
commonalities with distributed database. However, the intimacy between private
blockchain and deterministic database has never been studied. In essence,
private blockchain and deterministic database both ensure replica consistency
by determinism. In this paper, we present a comprehensive analysis to uncover
the connections between private blockchain and deterministic database. While
private blockchains have started to pursue deterministic transaction executions
recently, deterministic databases have already studied deterministic
concurrency control protocols for almost a decade. This motivates us to propose
Harmony, a novel deterministic concurrency control protocol designed for
blockchain use. We use Harmony to build a new relational blockchain, namely
HarmonyBC, which features low abort rates, hotspot resiliency, and inter-block
parallelism, all of which are especially important to disk-oriented blockchain.
Empirical results on Smallbank, YCSB, and TPC-C show that HarmonyBC offers 2.0x
to 3.5x throughput better than the state-of-the-art private blockchains.
