The Data Access And Integration Based On P2P Method Under Grid

Data management under grid condition is different from data management under traditional distributed environment: The databases under grid are usually large-scale with dynamic, autonomous and distributed. With the purpose to solve the problems that heterogeneity and diversity of source database, in order to adapt the data access and integration better under grid environment, the paper proposes the data access and integration based on P2P method under grid.Firstly, the paper proposes a data access and integration system GDSAI adapting to grid environment. The system is service based and specially adapted to data grid. It adopts a hybrid architecture and offers a wrapper/mediator-based approach to access and integrate data sources under gird. There are three main components of system: wrapper, distributed query processor and query recomposing engineer.Secondly, the paper develops the wrapper OGSA-EDAI of GDSAI system. The wrapper is expansion of OGSA-DAI. So, OGSA-EDAI not only could wrap the heterogeneous data sources and shield heterogeneity, but also does implement the buffer pool technology that can raise greatly the speed to access data sources. At the same time, the paper implements the interaction between wrapper OGSA-EDAI and distributed query processor OGSA-DQP and makes them accomplish the access and integration to physical data sources together.Lastly, to develop query recomposing engineer. It's function is to accept a XPath query given by user to local data source schema. By retrieving the schema mapping rule document, query restruction engineer finds the data sources connected to local data source and recomposes the query to get the queries to all data sources connected to local data source.