Md-Tree: A Search-Optimized Index Structure For Flash Devices

Flash memory provides significant performance improvement over HDDs, but are confronted with some unique challenges like write endurance and write amplifications. Designing of indexing data structures for flash memory has been an area of interest. In this work, we explore a new perspective in implementing B-trees on flash. Previous works have predominantly focused on improving the insert performance which compromised search performance. We propose ways to improves search performance without compromising insert performance using a novel concept of an optimized metadata to speed up the search performance. New ideas to smartly exploit the incremental 1-to-0 update properties of flash in interesting ways to improve the endurance are explored. Our experiments revealed 60% search response time improvement over the best of the alternative schemes. The problems addressed are also relevant to emerging areas like Non-volatile Memory (NVM).