分布式数据库中空间拓扑连接查询优化处理方法研究

摘要

Based on traditional distributed query processing and in combination of existing distributed cross -border fragment join optimisation, in this paper we present the transformation rules of relational algebra which are based on spatial fragment topological join .The query tree after data localisation processing is further simplified by making use of equivalent transformation rules .Then, we introduce some new concepts including join merging tree and execution plan tree .By using the corresponding merging and optimisation algorithm we transform the global spatial query to specific executions of the spatial databases in each local venue site .%在传统的分布式查询处理过程基础上，结合已有分布式跨边界片段连接优化方法，提出基于空间片段拓扑连接优化的关系代数转换原则。通过利用等价转换规则，进一步简化经过数据本地化处理后的查询树。引入连接归并树和执行计划树等概念，并利用相应归并和优化算法将全局空间查询转化为各个场地局部空间数据库的具体执行计划。