Integrated approach to buffer management and query optimization

Abstract

In today's relational database systems, query optimization and buffer managment are generally treated independently. However, the query acess plan contains information on data access patterns which can be useful hints to the buffer managment. Furthermore, the optimal access plans under different buffer sizes can be quite different. An intergated approach to buffer managment and query optimization is proposed and analyzed. The query strategy of all transaction types is simultaneously considered together with buffer allocation strategy so transaction response time, which is determined by the buffer allocation and query optimization strategies, an optimization method combining an interger programming model with a queueing model applied iteratively is developed to capture this effect. To reduce the size of the optimization problem. A methodology based on the concept of buffer consumption is proposed to pre-analyse the query and substantially cut down the number of access plans to be considered. A detailed simualtion is used to demonstrate the superiority of the intergated strategy as compared to other buffer management strategies based on working set and hot set.