The reasons we did a better job(from our own perspective) than RocksDB are: 1. We moved lots of code out side db_mutex (db mutex is convenient but costs too much) 2. We introduced a new KV separation implementation that we believe is better than RocksDB’s implementation (we didn't hear any production user are using RocksDB's KV separation yet) 3. We introduced a lazy compaction strategy that can delay compaction task while online services are dealing with short-time heavy writing. 4. Other optimizations like time histogram based TTL, pipelined WAL sync.