Study Of Version Management And Concurrency Control Of Engineering Database

Engineering Database Management System is an all-around software system. Both version management and concurrency control are critical parts of Engineering Database Management System. The iteration property of engineering design causes the high frequency of fetching versions out from the public library or adding versions into it and the long-term property of transactions. Firstly, we summarize the knowledge of version management model and method. Then we analyse existing problems in breadth and in depth probably occurring in the process of fetching versions out from the public library and in the process of adding versions into the public library. On the analysis and corresponding algorithms of graph, we give two specific and operable algorithms to solve the problems automatically. Secondly, we summarize and analyse the traditional concurrency control method of EDB .According to the existence of multiple different copies of one data object that is the existence of versions and according to the characters of long-term transactions, a new concurrency control method which is based on versions and is different from traditional lock method and time-stamp method is given in the paper. In this method, we use incremental and automatic version propagation export and import algorithms to export and import corresponding versions and their corresponding equivalent versions.