System and method for employing a grid index for location and precision encoding

• Main Authors: LOGAN RON, TOYAMA KENTARO
• Format: Patent
• Language: Chinese; English
• Published: 01.12.2004
• Edition: 7
• Subjects: ADVERTISING; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND,DEAF OR MUTE; CALCULATING; COMPUTING; COUNTING; CRYPTOGRAPHY; DIAGRAMS; DISPLAY; EDUCATION; EDUCATIONAL OR DEMONSTRATION APPLIANCES; ELECTRIC DIGITAL DATA PROCESSING; GLOBES; PHYSICS; PLANETARIA; SEALS

一个系统和方法，用于组合数据库条目的坐标值的精度估计，使得包括精度信息作为一维索引的部分。这是通过构造分层索引来完成的，其中网格的尺寸与坐标值的精度有关。网格索引是n-维空间网格化成网格空间的规则划分至网格单元，对于在空间中一个点x，存在一个索引函数index(x)，它为包含点x的网格检索一个唯一的整数值，以及一个函数坐标(y，s)，它以比例s返回与索引y相关联的点。分层的网格索引实际上是重叠在同一空间上许多具有不同尺寸网格单元的网格索引。在此情况下，每个函数使用一个附加的变元来指定要使用的网格单元的尺寸。因此，假定网格尺寸s是从一组网格尺寸S中提取的，Index(x，s)返回一个唯一的整数值用于包含点x的尺寸为s的网格。分层索引可用于增强数据库查询的性能。按小网格尺寸s#-[smal1]查找结果的查询，不查找在大网格尺寸s#-[large]上的匹配。能为有限区域A执行相似的计算。 A system and method for combining the precision estimate of a database entry's coordinate value such that the precision information is included as part of the one-dimensional index. This is done by constructing a hierarchical index in which the size of the grid is related to the precision of the coordinate value. A grid index is a gridding of an n-dimensional space into a regular partition of the grid space into grid units, for which for a point in space, x, there is a function index (x), which retrieves a unique integer value for the grid that contains Point x, and a function coordinate(y, s), which returns a point associated with the index y at scale s. A hierarchical grid index is effectively a number of grid indices overlaid on the same space, with grid units of different sizes. In this case, each of the functions employs an additional argument that specifies the size of the grid unit to use. Thus, assuming that the grid size, s, is drawn from a set of grid sizes, S, Index (x,s) returns a unique integer value for the grid of size s that contains Point x. Hierarchical indexes may be used to enhance the performance of database queries. A query that seeks results from a small grid size, s small , does not seek matches at a large grid size, s large . Similar calculations can be performed for a finite area A.