Emerging byte-addressable, non-volatile memories (NVMs) is revolutionary as the data written by a store operation of the CPU is nonvolatile. This talk presents the architecture of a prototype and performance evaluation results that demonstrate the potential of NVMs when they are used for the WAL buffer in PostgreSQL; a transaction becomes durable promptly after its WAL records are written in the WAL buffer. There is no need to wait the WAL records are written in the storage device. In a nutshell we can exploit the performance of asynchronous commit without impairing the transaction durability by using NVM for WAL buffer. Although the idea is simple, its implementation, however, is not. This talk also covers the difficulties to implement NVM WAL buffer and how to address them. Finally, I would like to share some knowledge that I obtained through the implementation and examination of the prototype.