基于闪存的混合存储系统缓冲区管理算法

由于基于闪存的混合存储系统充分利用了闪存的高速随机读和磁盘的快速顺序写的特性,近年来已经成为了数据库管理系统的二级存储层的高效存储模式,但其I/O访问开销是一个继续提高存储性能的瓶颈.为了降低混合存储系统的I/O访问开销,提出了一种自适应缓冲区管理算法DLSB.该算法根据数据页的逻辑代价和物理代价进行自适应的数据域选择；并在选择的数据域中,比较闪存队列和磁盘队列容量的实际值与理想值来确定数据页的置换,达到了提高I/O访问效率的目的.实验结果表明,该算法有效且可行,显著降低了混合存储系统的I/O访问开销.

Buffer management algorithm in hybrid storage systems based on flash memory

The hybrid storage system,based on flash memory and magnetic disk,has become an effective storage model of DBMS’s second storage layer by using high speed random read of flash memory and consecutive write of magnetic disk in recent years.But the access cost of I/O is a bottleneck for further enhancing its storage performance.To reduce the access cost of I/O in hybrid storage system,a self-adaptive buffer management algorithm named DLSB is presented.The algorithm,based on logical cost and physical cost of data pages,data region self-adaptively is choosed.And in the selected data region,the data page replacement is determined by respectively comparing the actual value and ideal value of flash sequence capacity and magnetic disk sequence capacity,then the access efficiency of I/O is improved.The experimental results show that the algorithm is effective and feasible.The I/O access cost of hybrid storage system.