XQuery Optimization In Heterogeneous Data Integration System

The integration of heterogeneous data sources, which can effectively make use of the information sources and data sharing, is a hotspot within the field of current data processing research. This paper firstly describes an architecture of heterogeneous data integration system based on a Mediator-Wrapper middleware, and then makes a deep research on the XQuery query processing, especially the key issues, such as query decomposition and optimization technology. Popular techniques of XQuery query processing are based on decomposition. XQuery has a complex syntax such as FOR clauses, and its complexity causes some considerations for the decomposition of global XQuery query. In this paper, we propose an algorithm to decompose a global query into local queries and to construct the result of the global XQuery query from the results of the local queries. Furthermore, it illustrates the realization of query decomposition and optimization with examples.