Abstract: In order to solve the problem that global query can not query heterogeneous data sources,this paper proposes to decompose the global query into subqueries against heterogeneous data. It designs query decomposition and subquery reconstruction algorithm. Query decomposition is based on JavaCC and JJTree to abstract the global query into a syntax tree. Subquery reconstruction algorithm traversals the syntax tree, chooses different reconstruction algorithms based on the current node type, and constructs the sunquery based on different datasource.

Key words: data integration, query decomposition, subquery reconstruction

摘要： 为解决全局查询无法直接查询异构数据源问题，提出将全局查询分解为针对异构数据源子查询的解决方案。设计面向多数据源异构数据的全局查询分解算法和子查询重构算法。全局查询分解算法基于JavaCC及JJTree工具将全局查询语句抽象成语法树。子查询重构算法遍历语法树，根据节点类型采用不同的重构算法，构造出针对不同类型数据源的子查询语句。

关键词: 数据集成, 查询分解, 子查询重构

CLC Number: 

• TP311