Cassandra and ScyllaDB: Similarities and Differences

ScyllaDB, initially perceived as a database chasing Cassandra to achieve feature parity, has evolved to offer unique features that distinguish it from Cassandra. Both databases share common ancestry from Google Bigtable and Amazon Dynamo, and they incorporate similar core features like keyspaces, tables, and basic operations through the Cassandra Query Language (CQL). However, ScyllaDB has introduced enhancements such as more efficient lightweight transactions and production-ready materialized views, which are distinct from Cassandra's implementations. While both databases support high availability and similar architectures, their design philosophies differ; ScyllaDB utilizes a shard-per-core approach for higher hardware utilization, whereas Cassandra relies on node-based sharding. Additionally, ScyllaDB provides unique capabilities like a DynamoDB-compatible API called Alternator and improved Change Data Capture functionalities. Despite these differences, the continuous development in both systems suggests an ongoing dynamic of convergence and divergence in features, presenting users with various reasons to choose between the two based on specific needs and capabilities.