RocksDB vs Tokudb: What are the differences?

RocksDB: Embeddable persistent key-value store for fast storage, developed and maintained by Facebook Database Engineering Team. RocksDB is an embeddable persistent key-value store for fast storage. RocksDB can also be the foundation for a client-server database but our current focus is on embedded workloads. RocksDB builds on LevelDB to be scalable to run on servers with many CPU cores, to efficiently use fast storage, to support IO-bound, in-memory and write-once workloads, and to be flexible to allow for innovation; Tokudb: Open source, high-performance storage engine for Percona Server. It is an open-source, high-performance storage engine for MySQL and MariaDB. It achieves this by using a fractal tree index. It is scalable, ACID and MVCC compliant, provides indexing-based query improvements, offers online schema modifications, and reduces slave lag for both hard disk drives and flash memory.

RocksDB and Tokudb can be categorized as "Databases" tools.

Some of the features offered by RocksDB are:

• Designed for application servers wanting to store up to a few terabytes of data on locally attached Flash drives or in RAM
• Optimized for storing small to medium size key-values on fast storage -- flash devices or in-memory
• Scales linearly with number of CPUs so that it works well on ARM processors

On the other hand, Tokudb provides the following key features:

• Fast and scalable service
• Better performance
• Stronger ROI

RocksDB and Tokudb are both open source tools. RocksDB with 17.1K GitHub stars and 3.86K forks on GitHub appears to be more popular than Tokudb with 609 GitHub stars and 111 GitHub forks.