What can Emerging Hardware do for your DBMS Buffer?

The spectacular development of business intelligence applications (BIA), built around the data warehousing technology, increases the demand on query performance of DBMS hosting with its extremely high amount of data. In such a context a high interaction among queries exists since they share a large number of intermediate results. This is due to the fact that BIA use relational schemes such as a star schema in which each join passes through the fact table. The decision to cache these intermediate results in the traditional buffer becomes a critical issue since it depends on the size of the buffer and the number of intermediate results candidate for caching. As flash memory is more and more adopted in mass storage systems, we rely on it to buffer some intermediate results. In this paper, we first propose to couple the RAM and Solid State Drive, to respond to the problem combining buffer management and query scheduling sub problems. Secondly, a cost model for evaluating the quality of buffering data and scheduling queries is given. Based on this cost model, an algorithm is given to solve our joint problem. Simulations show that our proposal enhances the performance of SQL queries up to 86%.