Persistent Memory Commit Accelerator reduces redo log write latency by using Persistent Memory and RDMA before flushing to Flash then disk. This helps to further reduce redo log write latency by utilizing the speed and low latency of Persistent Memory, along with the Remote Direct Memory Access (RDMA) protocol, to commit changes to disk faster. This allows the system to quickly commit changes to disk, resulting in improved performance and reduced latency.
This is according to the Oracle Exadata Database Machine X9M Implementation Essentials Official Text Book and Resources [1][2]. The Persistent Memory Commit Accelerator uses Persistent Memory and Remote Direct Memory Access (RDMA) technology to write redo log data to Flash and disk, resulting in improved latency and higher throughput. Additionally, the Accelerator tracks changes to Persistent Memory Data Accelerator to ensure duplicate blocks are not written to Flash [1], further reducing latency.