The Study Of The HMISC Based On Temporal Relational Model

The computer technology has been gradually applied to the industry, agriculture, research, education, health care and other fields. Database technology as an important component of the computer technology has accessed to a wide range of applications. The information recording in the database is the eigenvalue at a particular moment. If the eigenvalue change, new one will cover the old one. With the unceasingly expansion of the application, there has been a case that the presented and the future information are equally important as well as the present information in many issues. Therefore the people proposed the Temporal Database.The primary task in this paper includes: Firstly, it introduced the expression form of the time in computer, three kinds of times in the view of the computer (Valid Time, Transaction Time and User-defined Time), time and time point, time point and time interval as well as the temporal relations of two time intervals. Secondly, it introduced the current theory of the Temporal Database and two Temporal Expansion Methods. Thirdly, through the analysis of the function of the HMISC (Health Management Information System of Children), it has proposed a plan of the design and implementation about HMISC and established the corresponding Relational Model. Fourthly, it has carried on the analysis of the temporal data in the relational model, and then using the different temporal expansion methods to expand the different temporal data in the relational model and it has got the possible query methods in the Temporal Relational Model. Finally, it has done the study of the temporal relational model and the classification of the attributes in the model, proposed the HMISC Temporal Query Algorithm.It has used two expansion methods of the relational model in this paper. In the standard physical examination model and the EPI model, majority attributes are closely related with the time in every table. Therefore it has adopted the following temporal expansion method: it added a time attribute in every table. It has only considered children's name as the temporal attribute in the children basic model, therefore thetemporal expansion method that it adopted was to add the time attributes into the name attribute. In order to reduce other information's redundancy which was brought by the name change in the children information model, it has placed the name attribute and the added time attribute in another table.It divided attributes into CA (Constant Attributes), CTA (Constant Temporal Attributes) and TVA (Time-varying Attribute), proposing that TVA was a compound attributes being composed of one CA and an n-dimensional form CTA. It should be placed in the TVT (Time-varying Table). Finally, it has got the formula that can be used to search the scope that given time in the known time intervals.An available HMISC has been developed. The system has been used in the Secondary Clinical Hospital of Shanxi Medical College as well as many communities in Taiyuan, Datong and Xinzhou. It can be proved by the practice that the temporal expansion methods used in this paper is effective. It is possible to achieve the purpose of reducing the data redundancy through placing TVA into a TVT. In the end it can get the conclusion that the algorithm is available and validity.