The Semantics Description Of Data Element Alteration Management

The logic data model is the basic and key part of software development,As time goes on and performance demands of business developmenat,it must to be adjusted restructure a plan or design because of customer demand. logic model needs regular updating to satisfy the new requirements.So for the scalability of logic model and no change the sructure of the logic model, bring forward a study of the modification of the data element's semantics description.This thesis researches into theory and technology about description of data element and optimization of data model,and based on analyzing and comparing work of the other optimum method, a method is proposed to Semantics Description of data element.We use EXPRESS language to describe the adaptation rules. Adjust and improve the semantic constraints of data elements.the main contents include:(1) The study of index of optimizing the model:Through analyzing the characteristics of Structure Characteristic of logic model, the logic model be viewed as a complex network models. Principle of the Optimization Indexes wans presented,through the statistical analysis,the optimization indexes was presented,and the ways of calculation of indexes are given.(2) The method of semantics description of data element alteration:Based on optimization indexes and expand rules to improve the description of data element.(3) The alteration management of data element:In keeping with th logic data model,data dictionary and view must to be update and the method of automatic drawing ER map be researched.So we can understand and analyze the model easily.This paper described the realization of the extension and optimization,and key technology and alteration management are introduced. The optimal solution and data analysis showed the model based on entropy principle was feasible and effective.