Design and implementation of log management module in three-dimensional spatial database management system

Log management module plays an important role in the massive spatial database management system. Recently there are few three-dimensional spatial database management systems with pertinent log management sub-system, or the administrator can only use the log, which is attached by database system, to recover the data. To improve this issue, hierarchical structure of the log management module should be taken into account. The overall design of three-dimensional spatial database management system is as follows: three-dimensional spatial database (including database system, file system), three-dimensional spatial data engine, and three-dimensional space management tools. The log management module is designed to solve the problem of complexity and inconvenience of three-dimensional spatial data manipulation records. According to the 3D spatial database management system design, we divided the log management into three layers. The log management system includes monitor layer of three-dimensional spatial database's triggers and file database system operations recording statements, interface layer of log management module of three-dimensional spatial database engine, and graphical user interface layer of log management module of three-dimensional spatial data management tools. Monitor layer design includes database system trigger design. When the database table has been dynamically created, the trigger will be automatically created and record the database operations, then the file system calls function to record the log. Interface layer design includes accessing the database, reading the log table in database and other integrated operations, including query and delete. Graphical user interface layer mainly includes the design of graphical interfaces, the function call form interface layer, and log data operations. In order to work on the layers conveniently, database system trigger and file database system's record are used to record the operation of the database. The log module interface in three-dimensional spatial data engine is used to exchange the data between graphical interface and underlying database. The log module in database management tools can directly provide a graphical interface, but not need to provide access functions to get the log data. This design method has an excellent scalability and flexibility, and can also be made appropriate changes to meet the new needs.