A simple fast method is given for sequentially retrieving all the records in a B tree. A file structure for database is proposed. The records in its primary data file are sorted according to the key order. A B tree ...A simple fast method is given for sequentially retrieving all the records in a B tree. A file structure for database is proposed. The records in its primary data file are sorted according to the key order. A B tree is used as its dense index. It is easy to insert, delete or search a record, and it is also convenient to retrieve records in the sequential order of the keys. The merits and efficiencies of these methods or structures are discussed in detail.展开更多
Current electronic business activities involve a vast number of trading partners and different electronic documents.Usually different enterprises use different document formats.This is the well-understood problem of t...Current electronic business activities involve a vast number of trading partners and different electronic documents.Usually different enterprises use different document formats.This is the well-understood problem of the lack of information interoperability between applications in the e-business arena.It is required to construct an enterprise information model to harmonize different system data structures into a unified data structure.The purpose of this paper is to develop an E-Business information modeler,which will be a good tool to exchange the information between different business enterprises.This is a new approach to the well-understood problem of the lack of information interoperability between applications in the e-business arena.It will be a more flexible and interoperable way of standardizing Business Semantics.During the transformation,SMART theory is widely used in our system.SMART is meta-model to formally specify information structures in object orientation.It provides an object-oriented environment to express the canonical information model with one semantic structure,that is,class.SMART consists of a collection of views:there is a core view which we called canonical view,and also there are many different kinds of views around the core view.We can transform the core view to the around view as we need.展开更多
大部分XML查询技术都是基于某种对XML树的编码方法.对XML树的编码,是指按照某种规则对XML树的每一个结点分配唯一的编码,目的是通过任意两个结点的编码,能够直接判断两个结点之间是否具有祖先后代关系.最常用的编码方法是区域编码方法(r...大部分XML查询技术都是基于某种对XML树的编码方法.对XML树的编码,是指按照某种规则对XML树的每一个结点分配唯一的编码,目的是通过任意两个结点的编码,能够直接判断两个结点之间是否具有祖先后代关系.最常用的编码方法是区域编码方法(region based numbering scheme).然而,XML数据也会面临插入删除等更新问题.数据一旦更新,区域编码也要作相应的调整,才能保证基于这个编码的各种索引和查询算法的正确性.在编码的更新方面,目前研究得还不多.主要研究区域编码的更新问题,采用预留编码空间的方法,针对不同特征的XML数据和应用环境提出了一整套预留算法和编码更新算法,并做了大量的实验,检验这些算法的有效性.展开更多
文摘A simple fast method is given for sequentially retrieving all the records in a B tree. A file structure for database is proposed. The records in its primary data file are sorted according to the key order. A B tree is used as its dense index. It is easy to insert, delete or search a record, and it is also convenient to retrieve records in the sequential order of the keys. The merits and efficiencies of these methods or structures are discussed in detail.
基金Supported by"New Start"Academic Research Projects of Beijing Union University(zk10201412)
文摘Current electronic business activities involve a vast number of trading partners and different electronic documents.Usually different enterprises use different document formats.This is the well-understood problem of the lack of information interoperability between applications in the e-business arena.It is required to construct an enterprise information model to harmonize different system data structures into a unified data structure.The purpose of this paper is to develop an E-Business information modeler,which will be a good tool to exchange the information between different business enterprises.This is a new approach to the well-understood problem of the lack of information interoperability between applications in the e-business arena.It will be a more flexible and interoperable way of standardizing Business Semantics.During the transformation,SMART theory is widely used in our system.SMART is meta-model to formally specify information structures in object orientation.It provides an object-oriented environment to express the canonical information model with one semantic structure,that is,class.SMART consists of a collection of views:there is a core view which we called canonical view,and also there are many different kinds of views around the core view.We can transform the core view to the around view as we need.
文摘大部分XML查询技术都是基于某种对XML树的编码方法.对XML树的编码,是指按照某种规则对XML树的每一个结点分配唯一的编码,目的是通过任意两个结点的编码,能够直接判断两个结点之间是否具有祖先后代关系.最常用的编码方法是区域编码方法(region based numbering scheme).然而,XML数据也会面临插入删除等更新问题.数据一旦更新,区域编码也要作相应的调整,才能保证基于这个编码的各种索引和查询算法的正确性.在编码的更新方面,目前研究得还不多.主要研究区域编码的更新问题,采用预留编码空间的方法,针对不同特征的XML数据和应用环境提出了一整套预留算法和编码更新算法,并做了大量的实验,检验这些算法的有效性.
