The Implementation of Flash-aware Buffer Replacement Algorithms in PostgreSQL1

Flash memory is growing maturer in technology, larger in capacity and cheaper in price. Many companys begin to use flash-based solid state disk instead of magnetic disk nowadays. Moreover, personal computers such as macbook, are using flash-based solid state disks. On account of the different characteristics between flash -based solid state disk and magnetic disk, more and more researchers begin to design the algorithms for flash -based database. PostgreSQL is the most famous opensource database, but PostgreSQL is aimed at magnetic disk currently. In this paper, we implement the CF-LRU, CCF-LRU, CCCF-LRU algorithms and integrate them into PostgreSQL. Finally, we use BenchmarkSQL to do the performance tests. The experiment results show that the performance of PostgreSQL using CF-LRU, CCF-LRU or CCCF-LRU is better than PostgreSQL using original algorithm when PostgreSQL is running in a flash-based solid state disk.