An index management using CHC-cluster for flash memory databases

Flash memories are one of the best media to support portable and desktop computers’ storage areas. Their features include non-volatility, low power consumption, and fast access time for read operations, features which are sufficient to present flash memories as major database storage components for portable computers. However, we need to improve traditional index management schemes based on B-Tree due to the relatively slow characteristics of flash memory operations 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. The CHC-Tree-based index management scheme improves index operation performance by compressing the flash index nodes and clustering the hot–cold segments. The cold cluster compression techniques using unused free area in index node reduces the number of slow write operations in index node insert/delete processes. Our performance evaluation shows that our scheme significantly reduces the write operation overheads, improving the index update performance of B-Tree by 21.9%.