Opening the Door to SSD Algorithmics: Technical Perspective

write amplification of an arbitrary sequence of write operations. These algorithms expose the vital role “death times” play in minimizing write amplification, where the death time of a page is the next time the page is modified. Those familiar with the decades-old literature in memory cache management may recall Belady’s algorithm, which achieves the maximum cache hit rate by evicting pages accessed farthest in the future. The rough analogy between the two research areas where the time of future access of pages plays a critical role in algorithm design is difficult to miss. The formal study of algorithms and data structures for SSDs that explicitly account for write amplification and wear leveling is still in its infancy. In the current state of the art, software initially designed for other storage media is often retrofitted to work for SSDs based solely on empirical evaluation. A good model has historically been the key that opens the door to theoretical advances and algorithmic discoveries. The most significant impact of this paper is likely to come by attracting more research and researchers to the foundational study of SSD algorithmics. Given the ever-expanding role of SSDs in the modern computing universe, the benefits of such research can hardly be overstated.