A persistent key-value store for fast storage environments.

RocksDB is an embeddable persistent key-value store for fast storage.

Column-store features
When your database grows into millions of records spread over lots of tables and used in business or science data warehouse applications, you really want a column-store database management system.

MonetDB innovates at all layers of a DBMS, e.g. a storage model based on vertical fragmentation, a modern CPU-tuned query execution architecture, automatic and self-tuning indexes, run-time query optimization, and a modular software architecture.