RocksDB vs Tokudb: What are the differences?

Introduction: RocksDB and TokuDB are two popular storage engines often compared in terms of performance and features. Below are the key differences between RocksDB and TokuDB.

1. Data Compression: RocksDB utilizes a compression algorithm called LZ4 for data compression, which can significantly reduce storage requirements. In contrast, TokuDB offers Fractal Tree indexes that inherently compress the data, leading to a smaller disk footprint.

2. Write Amplification: RocksDB employs an LSM (Log-Structured Merge) tree architecture, which can result in higher write amplification compared to TokuDB's B-Tree approach. This can impact the overall write performance in scenarios with intensive write workloads.

3. Transaction Support: TokuDB provides full ACID compliance with multi-version concurrency control, supporting transactions at the row level. RocksDB, on the other hand, lacks built-in support for transactions and requires external handling through its API.

4. Storage Engine: RocksDB is primarily designed as an embedded storage engine, commonly used in systems like LevelDB and Apache Cassandra, while TokuDB is typically used as a plugin storage engine for MySQL and MariaDB, offering additional features like hot schema changes.

5. Performance Tuning: RocksDB offers more configuration options and tuning knobs for optimizing performance, allowing users to fine-tune parameters based on specific use cases. TokuDB simplifies performance optimization by automatically adjusting settings based on workload characteristics.

6. Open Source vs. Commercial: RocksDB is an open-source project maintained by Facebook, providing transparency and flexibility for developers to contribute and customize the code as needed. In contrast, TokuDB is a commercial product offered by Percona, requiring licensing for certain production use cases.

In Summary, RocksDB and TokuDB differ in data compression, write amplification, transaction support, storage engine usage, performance tuning options, and licensing models.