rocksdb

RocksDB is a persistent key-value store library developed and maintained by Facebook's Database Engineering Team. It builds on earlier work on LevelDB by Sanjay Ghemawat and Jeff Dean. The project is intended as a core building block for a fast key-value server, especially for data stored on flash drives. The library uses a Log-Structured-Merge-Database (LSM) design. According to the README, it offers flexible tradeoffs between write amplification factor (WAF), read amplification factor (RAF), and space amplification factor (SAF). It includes multi-threaded compactions, which the README presents as making it suitable for storing multiple terabytes of data in a single database. The public interface is contained in the include directory. Callers should not include or rely on details of any other header files in the package, because those internal APIs may change without warning. Example usage is available in the examples directory on GitHub, and further explanation is available in the GitHub wiki. RocksDB is dual-licensed under GPLv2 and Apache 2.0, and users may choose either license. The README also points to a Facebook developers group and a Google Groups email list for questions and discussions.