A TDBMS Extension Based On Temporal Functinal Dependency Module

Time is the all-pervasive nature of objective attribute,all information has the corresponding temporal properties.Time as the data attribute of temporal database data has been incorporated into the properties of the systems management area,for storage and management of multiple-time data.The temporal data stored in temporal database have temporal information,when we bring functional dependency in the classical relational database into the temporal database,the function dependency also needs to increased state information to illustrate the establishment of the time of functional dependency,such as:"any employee in the same month only has one wage","any employee in the same year only work in the same department",compared to classic functional dependency,we record:Nameâ†'_<月>Sal,Nameâ†'_<å¹´>Dept,and saying they are temporal functional dependency.Clearly,temporal functional dependency if more effectively modeling real-world objects, and can effectively solve the problem of redundant datas in database and data constraints.After more than 20 years of development,the temporal database theoretical study has been made fruitful achievements,and temporal database technology to achieve still at the fledgling stage,at home and abroad do not have a real sense of the temporal database management system.As a commercial DBMS front-end components,TimeDB basically achieved the temporal data management functions,it is a successful database management system prototype.Based on the above considerations,This paper analyses the TimeDB method,the study states in the database at the temporal function dependent on the achievement.But at present the TDBMS did not provide temporal functional dependency support at the state function dependent on the definition,interpretation and inspection procedures by the user to achieve.How TDBMS expands functional dependency in the relational database, increasing temporal information,when inserting and modifying data in the TDBMS functional dependency checks the data and rollback the transaction which don't satisfy the dependency,and allows user-defined functional dependency,all about is an important research topic in the field of temporal database application.This paper presents an expansion of TimeDB based on temporal dependecy processing module,implements the support of temporal functional dependency in the temporal database,and supports user-defined temporal functional dependency.In this paper,we presents the historical background,origin and development of the temporal database,as well as the status quo of research and application, illuminate some basic concepts in the temporal database,followed states the expression scheme of the temporal data model and temporal data,and then system design of discussed the temporal database based on TimeDB extension,at last concludes temporal functional dependency and Derivation justice system,and this on the basis of the temporal functional dependency processing module.This paper presents the temporal functional dependency processing module as an extension of the existing functional modules,components TimeDB on the front end, used to support the TDBMS rely on the state function when handling characteristics. When users to insert and modify TDBMS operation,temporal function will rely on processing module insertion and modification of data inspection,only to rely on when to meet TimeDB implementation,not meet directly on the user tips,and support users Since the definition of state-dependent function of the temporal function dependent on the interpretation and processing is transparent to users.