| Information Integration is to use one or more database or some other information sources,which makes the data from from these information sources merge together, that like the processof using a single sources. In the information integration system, a mediator system allows usersto pose query on the global view and get answers from multiple information sources. In thispaper, it mainly discuss and research issues related to dynamic information sources ininformation integration. The GAV schema as a part of the LAV mode, then do query process tousers’ command. In the LAV mode, the data source description base on global model. LAVmode’s most prominent advantage is good extensibility, especially suitable for informationsources that change more frequently, when the data source pattern changes, don’t need toredefine the global model, only need to add a data source schema mapping. But compared withGAV model, the query rewriting of LAV is more complicated. In practice, because of datasources’ large number, the data sources’ frequent update and delete, easy extensibility of LAV isextremely important.This paper’s research is based on the Wrapper/Mediator integration framework, in the modeof LAV, the research of dynamic data source integrate method is put forward, at first, to a steadyinformation source supporting GAV schema(solid information source can be empty), researchits integrate method; secondly, on the basis of the stable source, increase extension of theinformation source, it is composed of dynamic information source’s exporting, base on it toresearch the integrate method. This paper’s main research content includes the querydecomposition: for the query decomposition that based on the LAV mode, query conditions thatcontained sub query, to solve the query decomposition；query rewriting based on the view: Inthe LAV mode, discuss the query rewriting based on the view and algorithm analysis；LAVquery rewriting algorithm validation：propose the example validation to the algorithm。... |
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