Research And Application Of Query Technology For Federated Database System

Federated Database System adapts to the need of getting data from different data sources,integrates different database management systems,brings out the interoperate of differernt systems,provides customers an uniform and transparent user interface, meanwhile,it maintains the completeness,uniformity and security of data across different systems.This paper compares the similarities and differences on the query processing between traditional database and Federated Database,studies the way of query processing in allusion to the Federated Database,also gives the design and implemention of Federated Database Query System based on the Federated Database Architecture and 3-tier Architecture Pattrn.This paper uses the Federated Database theory and technology mainly to study the solution and the method of Federated Database query processing.Below are the main tasks which the author studied and brought out:1) Studying Federated Database Architecture,designing the system architecture which suits the request of the Federated Database query system combining with the 3-tier Architecture Pattern.2) Combining with the features of autonomy,isomerism and distributivity of Federated Database,designing system architecture,solving the problem of isomerism and distributivity in the precondition of maintaining the autonomy of each component database.3) Studying and analysing the feature of Federated Database query processing, solving the problem of the global query division and query optimizing,mainly analysing the resolving of various situations among query division.4) Solving the management of each component database and Federated Database metadata,which includes the getting and setting of Federated Database metadata,the processiung of all levels' schema mapping and various isomerous conflict.5) Designing and implementing Federated Database query system,summarizing and analysing of the system's autonomy,isomerism and distributivity,etc.The implementation technology of Federated Database Query System based on 3-tier Architecture Pattern,which studying,implementing and summarizing by this paper,has consideration meaning in studying and software develpoing in the domain of integrating different databases.The achievement of this paper supports the application of related theories of Federated Database Query System,it is useful for the further development and use of Federated Database technology.