The Interoperation Between Spatial Data And Attribute Data Using Database Federation

As the rapid development of computer technology and networking technology, the environment of computer calculation has transferred from integrated into distributed, and the using of online transaction process systems in the internet environments is more and more popular. But the information are usually stored in different databases, for example: Microsoft SQL Server, Oracle, DB2, these databases are different in some abstract levels. In order to access into and operate the data from over one different database simultaneous, generate the concept of interoperation between different databases. Database federation can be an effective technology to solve this problem.Nowadays, there are many Geographical Information Systems and lots of spatial data in there, the article do a deep research on the data interoperation of these GIS and other related MIS systems. Through the interoperation of these two different database systems, we can add some spatial attributes to the original MIS systems, and can do some spatial analyzing, in this way can extend the functions of the MIS systems easily and rapidly.The article use database federation in order to achieve the interoperation. Through the systemically research on the theory of database federation technology, and deeply probed into its key parts, finally achieved to use database federation form a flat to do interoperation between two different data source: IBM DB2 and Oracle 9i, and let the spatial data in Oracle database and attribute data in IBM DB2 can share each other and do interoperation.The article contains seven chapters. The first two chapters discuss the development of the theory of database federation technology, and explain the latest researches about it, like: classification, features, structure, core problems and so on. The third chapter systemically analysis the implement of database federation's data flows to show how federation works, like the registration of wrapper, data formation, query operation and so on. The forth chapter discuss the key components which are important to database federation, like federation server, federation database, database federation system index, wrapper, user mapping, data type mapping, function mapping and so on. The fifth chapter introduces the procession of developingdatabase federation and try out each component to achieve data federation. The sixth chapter is an experiment, to carry out data interoperation between a GIS system and a MIS system. The last chapter is a conclusion about using of database federation to solve data federation on a DBMS level, and give a further prospect on this technology.To achieve data interoperation between different databases, we can use other system's data resources, and extend the existing system's functions. Also it can reduce some certain process like database design or data import, this can accelerate the developing efficiency largely. Further more, the sharing of some public system's data resources can assist government and enterprises to make decision effectively. Through this research and experiment, we found many good features on database federation technology, like the transparency in data accessing; the integrality > consistency and security of data management under DBMS level; and the autonomy of each sub-systems. In addition, the flat we formed to federate a GIS database system and a MIS database system can be a good spatial extend to many MIS systems, these are positive significances and s'ocial wealth of this technology.