基于最长属性路径过滤的SPARQL查询优化  

SPARQL Query Optimization Based on Longest Property Path Filtering

作　　者：林晓庆 张富[1] 程经纬 LIN Xiaoqing;ZHANG Fu;CHENG Jingwei(School of Computer Science and Engineering,Northeastern University,Shenyang 110819,China;School of Information Engineering,Eastern Liaoning University,Dandong,Liaoning 118003,China)

机构地区：[1]东北大学计算机科学与工程学院,沈阳110819 [2]辽东学院信息工程学院,辽宁丹东118003

出　　处：《计算机工程》2018年第11期7-13,共7页Computer Engineering

基　　金：国家自然科学基金(61672139);辽宁省自然科学基金(2015020048)

摘　　要：SPARQL查询过程中产生的大量中间结果严重影响查询效率。针对该问题,提出一种两阶段的查询优化方法。在第一阶段,将查询内含有相同变量的联结划分为一块,通过计算每块内的选择度重新排列联结。在第二阶段,利用属性路径索引对剩余的联结进行中间结果过滤。实验结果表明,该方法能够有效减少查询的中间结果,提高查询的执行效率。A large number of intermediate results during executing SPARQL query greatly affect the query efficiency.For this,a query optimization method with two phases is proposed.In the first phase,it divides a query that contains the same variable into a block by calculating the selectivity within each block to rearrange the join.In the second phase,it emploies the longest property path index to filter intermediate results.Experimental results show that the proposed method can effectively reduce the number of intermediate results and improve the query performance.

关 键 词：资源描述框架 SPARQL查询 选择度 属性路径 三元组过滤 中间结果 

分 类 号：TP311.13[自动化与计算机技术—计算机软件与理论]