Design And Application Of The Low Frequency Maintenance Database

We usually use the relational database to manage the general data in the management fieid,and the application of relational database can reflect the relationship between the data well,such as the teaching management system,which is based on the relational database model.In the mapping field,in the case: the Arc GIS commonly uses Geodatabase to manage the spatial data.GDB is actually based on the relational database management system technology.But the study found that,regardless of the traditional relational database or Geodatabase,the relationship structure is relatively complicated,and the data is more dispersed.And In order to facilitate maintenance data for data managers latterly.However,there are some data is almost no maintenance in the long-term,so that the mission in the late maintenance phase of is not the key consideration scope.According to the data,this paper proposes a new concept of "low frequency maintenance database".In this paper,comparing with the traditional relational database,the theory and the characteristics of the "low frequency maintenance database" will be introduced.The theory includes the basic concept and the application prospect of the database,and the application prospect is illuminated through the administrative databases,the management information database of ancient books and the title database of the mapping framework.The characteristics includes long-term maintenance cycle,the structure simplification and the high data confidentiality.At last,all these are the theoretical basis of this paper,and prove the significance of the database model.Because the symbols in the symbol database of the the mapping frame are designed on the basis of the national or industrial standards,it can meet the requirements of the low frequency maintenance database.In this paper,through the analysis of the structure of the symbol in the symbol system,and through the three stages of conceptual design,logical design and physical design to create the symbol database in accordance with the "low maintenance database mode".On this basis,then design the storage model of symbol,the method of encryption and decryption and the scheme of retrieval.The storage model is based on the "template---period" and the tree structure storage,and the method of encryption and decryption is based on DES,the retrieval is in accordance with the storage model and the method of encryption and decryption to design an effective scheme.In this paper,the symbolic rendering module,including access to the symbol database and layer symbol rendering,through the object-oriented idea,design interface,and explain the meaning of the interface including the attribute meaning and method description.After the symbol database is created which is based on the "low frequency maintenance" idea to design,it is compared with the symbol database based on the traditional relational database model,including the structure,the data compression,the data confidentiality and the data retrieval efficiency.Finally,test the rendering effect of the symbol database apply to the mapping framework.At last,the paper summarizes the innovation and the work of this paper,and puts forward the prospect and further research direction.