Decision Support Design And Implementation Of Olap Generic Components In The System

On-Line analytical processing (OLAP) is a recent and important application of database systems. Typically, OLAP data is presented as a multidimentional "data cube". OLAP queries are complex and can take many hours or days to run, if executed directly on raw data. The most common methods of reducing excution time is to precompute some of queries into summary tables (subcubes of the data cube) and then to build indexes on these summary tables.In most commercial OLAP systems today, the summary tables that are to be precomputed are picked first, followed by the selection of appropriate indexed on them.Since queries are often take many hours and since the statistical property of database are time-varying, it should be the responsibility of the optimizer to consider the alternative execution plans and to make a cost-based decision whether or not to use materialized views to answer a given query on a database.This paper has eight main sections: section one introduces the research status in this field , technical line, main work that we had done; Section two proposes DSS system architecture and the implement of this system. It introduces the main function of this system and gives some concrete example of its implement; Section three introduces the key technologies in implement this DSS system, such as Data WareHouse, OLAP and DataMing; From section four, we proposed a general model of the OLAP engine, a Database Connection model, a performance-optimizing model and a practical secure model. The general model of the OLAP engine is the core model in this system; it realizes the main functions of OLAP such as drill-down, roll-up, pivot and so on; it uses the techniques of data separation to improve the time efficiency, and it reasonably store and use the banking data model;the model of database connection is the base of the system, because it provide the connection between the middle ware and the database; we raise a solution for integration of heterostructure of database; We developed a secutity model which effectively solve the authentication and client privacy problem in the system;This model have the main features of security, flexibility and easy to deploy; section eight give some test on this system and give some improving direction.This system of the general component resolves several important problems, for example: functionality, performance, security, presentation and so on. The generality and the independence of platform is the component's major advantage, so the component can be applied to other industry and business department. Maybe the development of solution will promote the accessing of the data warehouse from WEB.