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
This paper studies and analyses the character of the tree structure,and then presents an algorithm which is concise and convinent for the construction of tree structure.It is especially fit for the application system ...This paper studies and analyses the character of the tree structure,and then presents an algorithm which is concise and convinent for the construction of tree structure.It is especially fit for the application system using database.The special storege organization needn’t to be established in the database using this algorithm.By SQL statement,the data dispersed in different storeage organization can be dynamically combined into the data set including two fields:father node field and child node field.Then the algorithm can process those data and display the tree structure rapidly. At last,we design a control called TFDTreeView which inherits from TTreeView control using this algorithm. TFDTreeView control provide a interface function,through which we can construct the tree structure convinently. On some occasions,this method will be good for the application system.And ,by building the control ,we can reuse it in many system development.展开更多
This paper presents a simple complete K level tree (CKT) architecture for text database organization and rapid data filtering. A database is constructed as a CKT forest and each CKT contains data of the same length. T...This paper presents a simple complete K level tree (CKT) architecture for text database organization and rapid data filtering. A database is constructed as a CKT forest and each CKT contains data of the same length. The maximum depth and the minimum depth of an individual CKT are equal and identical to data’s length. Insertion and deletion operations are defined; storage method and filtering algorithm are also designed for good compensation between efficiency and complexity. Applications to computer aided teaching of Chinese and protein selection show that an about 30% reduction of storage consumption and an over 60% reduction of computation may be easily obtained.展开更多
大量GIS应用的地图显示功能具有多尺度特性 .Hilbert R Tree索引与此特性不相适应 .使用它访问绘图数据存在I/O粒度偏小和同等级簇聚程度低两个问题 ,导致访问效率不高 .该文对它作出改进 ,提出一种新型索引即多级Hilbert R Tree索引 (H...大量GIS应用的地图显示功能具有多尺度特性 .Hilbert R Tree索引与此特性不相适应 .使用它访问绘图数据存在I/O粒度偏小和同等级簇聚程度低两个问题 ,导致访问效率不高 .该文对它作出改进 ,提出一种新型索引即多级Hilbert R Tree索引 (HierarchicalHilbert R Tree ,HHRT) .HHRT解决了上述两个问题 .实验证明后者的访问效率比前者有较大的提高 .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.
文摘This paper studies and analyses the character of the tree structure,and then presents an algorithm which is concise and convinent for the construction of tree structure.It is especially fit for the application system using database.The special storege organization needn’t to be established in the database using this algorithm.By SQL statement,the data dispersed in different storeage organization can be dynamically combined into the data set including two fields:father node field and child node field.Then the algorithm can process those data and display the tree structure rapidly. At last,we design a control called TFDTreeView which inherits from TTreeView control using this algorithm. TFDTreeView control provide a interface function,through which we can construct the tree structure convinently. On some occasions,this method will be good for the application system.And ,by building the control ,we can reuse it in many system development.
文摘This paper presents a simple complete K level tree (CKT) architecture for text database organization and rapid data filtering. A database is constructed as a CKT forest and each CKT contains data of the same length. The maximum depth and the minimum depth of an individual CKT are equal and identical to data’s length. Insertion and deletion operations are defined; storage method and filtering algorithm are also designed for good compensation between efficiency and complexity. Applications to computer aided teaching of Chinese and protein selection show that an about 30% reduction of storage consumption and an over 60% reduction of computation may be easily obtained.
文摘大量GIS应用的地图显示功能具有多尺度特性 .Hilbert R Tree索引与此特性不相适应 .使用它访问绘图数据存在I/O粒度偏小和同等级簇聚程度低两个问题 ,导致访问效率不高 .该文对它作出改进 ,提出一种新型索引即多级Hilbert R Tree索引 (HierarchicalHilbert R Tree ,HHRT) .HHRT解决了上述两个问题 .实验证明后者的访问效率比前者有较大的提高 .
