RocksDB
RocksDB is a high performance[1][2][3][4][5] embedded database for key-value data. It is a fork of LevelDB which was then optimized to exploit many central processing unit (CPU) cores, and make efficient use of fast storage, such as solid-state drives (SSD), for input/output (I/O) bound workloads. It is based on a log-structured merge-tree (LSM tree) data structure.