Transaction Management for Flash Media Databases in Portable Computing Environments

Flash memory is becoming a major database storage in building embedded systems or portable devices because of its non-volatile, shock-resistant, power-economic nature, and fast access time for read operations. Flash memory, however, should be erased before it can be rewritten and the erase and write operations are very slow as compared to main memory. Due to this drawback, traditional database management schemes are not easy to apply directly to flash memory database for portable devices. Therefore, we improve the traditional schemes and propose a new scheme called flash two phase locking (F2PL) scheme for efficient transaction processing in a flash memory database environment. F2PL achieves high transaction performance by exploiting the notion of the alternative version coordination which allows previous version reads and efficiently handles slow write/erase operations in lock management processes. We also propose a simulation model to show the performance of F2PL. Based on the results of the performance evaluation, we conclude that F2PL scheme outperforms the traditional schemes.