Research And Implementation On The Interoperation Method Of The Multi-source And Heterogeneous Data

Multi-Source data are necessary parts of information system. There are two kinds of Multi-Source data. One is Structured data, and the other is unstructured data. Recently database is always used to manage Structured data. But the unstructured data such as image, video, GIS data, and CAD drawings are still managed only by file system. This two kinks of data are storied separated, and have their own operating method. In the hydrological field data storing have characteristics of enormous capacity and diversity. Hysteretic of standards leads to lower efficiency of data exchange and interoperation. This paper study Multi-Source data in the hydrological field, raise an interoperation solution of Multi-Source.First, the paper introduces the characteristic of Multi-Source data and application, analysis the different storage method of the Multi-Source data, use separating storage method for unstructured data. Second, the paper raises an interoperation method model of the Multi-source and Heterogeneous Data based on the storage method, data dictionary and the XML technology. Directed against the security problem in using the separating storage method for unstructured data file and its attribution, this paper shows a "monitor" method to protect the non general destroy to the unstructured data file and hold the identity of source file and its attribution in the database. Then, the paper analysis the Heterogeneous database to find the reason of heterogeneity, design the data dictionary. Finally, the paper introduces Implementation on the Interoperation Method of the Multi-source and Heterogeneous Data.This paper use XML to carry data during the data exchange. Data and information are separated by program, and then written into two different XML files. The unstructured data are delivered as attachment with XML files. System receives the XML files, compare the information file with data dictionary to generate mapping rule file, apply mapping rule to data file. The result data file is used to update the database and the file system.