ScyllaDB
An optimised version of Cassandra, written in C++ to get rid of java gabage collection
Use LSM Tree (Log Structured Merge Tree) which remove the need of lock. DynamoDB would use B+ tree and Lock requires.
Support lightweight ACID via Paxos/Raft. ScyllaDB has "shard-per-core" (1 shard = 1 CPU core) architecture that can support high throughput of write in parallels.
Use case
- Very very high write/read throughput needed
- lightwieght ACID is acceptable
Cons