A Compressed Hot-Cold Clustering to Improve Index Operation Performance of Flash Memory-SSD Systems

플래시메모리-SSD의 인덱스 연산 성능 향상을 위한 압축된 핫-콜드 클러스터링 기법

  • 변시우 (안양대학교 디지털미디어공학과)
  • Published : 2010.01.31


SSDs are one of the best media to support portable and desktop computers' storage devices. Their features include non-volatility, low power consumption, and fast access time for read operations, which are sufficient to present flash memories as major database storage components for desktop and server computers. However, we need to improve traditional index management schemes based on B-Tree due to the relatively slow characteristics of flash memory operations, as compared to RAM memory. In order to achieve this goal, we propose a new index management scheme based on a compressed hot-cold clustering called CHC-Tree. CHC-Tree-based index management improves index operation performance by dividing index nodes into hot or cold segments and compressing pointers and keys in the index nodes and clustering the hot or cold segments. The offset compression techniques using unused free area in cold index node lead to reduce the number of slow erase operations in index node insert/delete processes. Simulation results show that our scheme significantly reduces the write and erase operation overheads, improving the index search performance of B-Tree by up to 26 percent, and the index update performance by up to 23 percent.


Hot-cold segment clustering;Tree indexing;Index compression;Flash memory


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