1. Wuhan National Laboratory for Optoelectronics, Key Laboratory of Information Storage System, School of Computer Science and Technology, Huazhong University of Science and Technology, Ministry of Education of China, Wuhan, China
2. Computer Science and Engineering Department, University of Texas at Arlington, Arlington, TX, USA
3. PingCAP, Beijing, China
4. Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China