摘要
将遗传算法与模拟退火算法相结合,导出了一种基于遗传-模拟退火算法的多连接查询优化算法.该算法将查询计划的一棵语法树看作是一个染色体,对于语法树上的连接操作后序遍历生成一个编码.在所有编码构成的种群进行完选择、交叉、变异操作之后,在其中引入模拟退火机制,从而进一步调整优化了种群,保持了群体的多样性,减少了用户查询的响应时间.
An idea of using genetic algorihtm and simulated annealing algorithm into query optimization is proposed. This algorihtm takes syntax tree as a chromosome,and its posterorder search result acts as a code. After the process of population selection, cross and variation, simulated annealing mechanism is introduced for further population optimization, which keeps population diversity and reduces customer response time.
出处
《大连交通大学学报》
CAS
2009年第5期85-87,共3页
Journal of Dalian Jiaotong University
关键词
查询优化
优化算法
遗传算法
模拟退火算法
query optimization
optimization algorithm
genetic algorihtm
simulated annealing algorithm
