An efficient database management scheme for portable information devices

Recently, a flash memory has become a major data storage in building portable information devices because of its non-volatile, shock-resistant, power-economic nature, and fast access time for read operations. The flash memory, however, needs to be erased before write operations which are very slow as compared to standard main memory. Therefore, traditional data control mechanisms are not easy to apply directly to a flash memory database, and so we propose a new scheme called flash aware transaction management (FATM) scheme for efficient transaction processing in a flash memory database environment. We also exploit segment-dependent variable lock granularity and segment-based lock management. FATM achieves high transaction performance by using a W-Cache and a double queue to overcome the effect of slow write and erase operations in transaction scheduling processes. We also propose a simulation model to show the performance of FATM. Simulation results show FA TM outperforms the traditional schemes on flash memory.