An Effective Semantic Cache for Exploiting XPath Query/View Answerability

来源 :计算机科学技术学报(英文版) | 被引量 : 0次 | 上传用户:xiao0mai
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Maintaining a semantic cache of materialized XPath views inside or outside the database is a novel, feasible and efficient approach to facilitating XML query processing. However, most of the existing approaches incur the following disadvantages: 1) they cannot discover enough potential cached views sufficiently to effectively answer subsequent queries; or 2) they axe inefficient for view selection due to the complexity of XPath expressions. In this paper, we propose SCEND, an effective Semantic Cache based on dEcompositioN and Divisibility, to exploit the XPath query/view answerability. The contributions of this paper include: 1) a novel technique of decomposing complex XPath queries into some much simpler ones, which can facilitate discovering more potential views to answer a new query than the existing methods and thus can adequately exploit the query/view answerability; 2) an efficient view-section method by checking the divisibility between two positive numbers assigned to queries and views; 3) a cache-replacement approach to further enhancing the query/view answerability; 4) an extensive experimental study which demonstrates that our approach achieves higher performance and outperforms the existing state-of-the-art alternative methods significantly.
其他文献
外语教学中文化导入的层次分为词语方面的文化;语用文化;精神、心理文化。外语教学中文化导入的方法有进行汉英文化对比研究、让学生阅读大量文学作品等。 Foreign language t
活塞的热疲劳性能对柴油发动机的全寿命至关重要。由于能量有限和可控性差等缺点,现有实验系统均不能满意地进行活塞热负荷模拟实验。为此,提出并建立了一套激光诱发活塞热负
提出高校学报基于学校重点学科形成高校学报“大专业小综合”的办刊模式.论述了基于重点学科的高校学报“大专业小综合”的内涵.通过成功范例论证了“融合学术分科,回归传统
近些年,学术期刊吸引力的不断下降促使办刊人转变“作者本位”的办刊思想,树立“读者本位”的办刊理念。为了更好地服务读者,我们首先必须明确刊物的定位,其核心在于读者定位
该文以民国时期中央研究院植物研究所主办的科学期刊《植物学汇报》为中心,考察了植物研究所的沿革、学科建设、刊载论文、作者群体、期刊特点等内容,展现了在时局动荡、经费
科技期刊质量的保证是要有高水平的稿件,要得到高水平的稿件需要编辑主动约稿。医学期刊编辑要发挥专业优势,广泛约稿。笔者根据自己的约稿经验,就约稿前的准备、约稿的形式
AIM:To determine the long-term outcomes regarding reinfection with Helicobacter pylori(H.pylori)and endoscopic changes after successful H.pylori eradication. ME
Conjoined twins are very rare with an estimated incidence of about 1 in 200 000 births with a male-female ratio of 1:3.1 The separation of conjoined twins prese
某泵站在基坑开挖至136.6m设计高程中粗砂岩及局部粉细砂岩时出现了涌水流砂情况,致使基坑底部开挖无法进行,经工程建设指挥部组织有关专家分析透水流砂原因,即在原基坑开挖
A high-performance capillary electrophoresis with amperometric detection(CE-AD)method has been developed for the analysis of seven bioactive ingredients,namely