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一种基于对象快照模型的时空查询原子模型 被引量:4
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作者 刘岳峰 康葳 《北京大学学报(自然科学版)》 EI CAS CSCD 北大核心 2015年第4期755-762,共8页
基于对象快照模型,在分析时空对象最基本时空特征的基础上,定义时间范围、空间范围、时空范围、时间关系、空间关系和属性状态6个基本查询元素。在此基础上,以时间为主轴,定义原子查询类型,并提出基于原子类型构造新类型的方法。对基本... 基于对象快照模型,在分析时空对象最基本时空特征的基础上,定义时间范围、空间范围、时空范围、时间关系、空间关系和属性状态6个基本查询元素。在此基础上,以时间为主轴,定义原子查询类型,并提出基于原子类型构造新类型的方法。对基本元素和原子查询的定义不涉及应用级语义,使其具有良好的系统性和适应性;同时具有明确的GIS表达,使其具备可实现性。研究成果可以作为时态GIS中时空查询接口实现的基础和依据。 展开更多
关键词 对象快照模型 时空查询模型 时态GIS
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Comparisons of three data storage models in parametric temporal databases 被引量:5
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作者 Seo-Young NOH Shashi K. GADIA Haengjin JANG 《Journal of Central South University》 SCIE EI CAS 2013年第7期1919-1927,共9页
The parametric temporal data model captures a real world entity in a single tuple, which reduces query language complexity. Such a data model, however, is difficult to be implemented on top of conventional databases b... The parametric temporal data model captures a real world entity in a single tuple, which reduces query language complexity. Such a data model, however, is difficult to be implemented on top of conventional databases because of its unfixed attribute sizes. XML is a matured technology and can be an elegant solution for such challenge. Representing data in XML trigger a question about storage efficiency. The goal of this work is to provide a straightforward answer to such a question. To this end, we compare three different storage models for the parametric temporal data model and show that XML is not worse than any other approaches. Furthermore, XML outperforms the other storages under certain conditions. Therefore, our simulation results provide a positive indication that the myth about XML is not true in the parametric temporal data model. 展开更多
关键词 data representation parametric data model XML-based representation
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