Association for Computing Machinery
Transaction-based systems often rely on Write-Ahead Logging (WAL) algorithms designed to maximize performance on disk-based storage. However, emerging fast, byte-addressable, Non-Volatile Memory (NVM) technologies (e.g., phase-change memories, spin-transfer torque MRAMs, and the memristor) present very different performance characteristics, so blithely applying existing algorithms can lead to disappointing performance. This paper presents a novel storage primitive, called Editable Atomic Writes (EAW) that enables sophisticated, highly-optimized WAL schemes in fast NVM-based storage systems. EAWs allow applications to safely access and modify log contents rather than treating the log as an append-only, write-only data structure, and the authors demonstrate that this can make implementating complex transactions simpler and more efficient.