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Engineering Database System, A Number Of Issues

Posted on:1998-07-23Degree:DoctorType:Dissertation
Country:ChinaCandidate:Q P WangFull Text:PDF
GTID:1118360185995562Subject:Computer applications
Abstract/Summary:PDF Full Text Request
This thesis discusses several research results on engineering database management system(EDBMS) for distributing integrated cooperative CAD system, which mainly includes an engineering database conceptual design method of logical layer-relationship, version management, distributed services, concurrent control, and the implementation of an expansive EDBMS based on EDBMS.In views of characteristic of distributing integrated cooperative CAD system , an engineering database(EDB) design method of logical layer-relationship is presented, which supports the conceptual design of EDB. It has not only entity-relationship(ER) modal function but also basic object-oriented(OO) modal function such as object, complex object. In the EDB design process, the classification of EDB is enforced. With classifying, decreases the data redundancy of EDB, enhances the consistent of data.For the distributing integrated CAD system, a tiers version management strategy of EDBMS is introduced. It consists of the designing object version and the system version of the project. This version control facilitates the designing process of complex and delicate problems, to better support distributed cooperative designing.In version control of single-user EDBMS, a model based on the version path is presented. In this model, version control is based on path of version derived, that is to say, all version operators will be processed according version derived path. It include the record difference and forwarding management strategy. Except the original version, all other version only stores renew data. In this model concept of multiply version inheritance and the shortest version path are proposed. This version mechanisms based on these concepts provide efficient version management, which decrease time of recovering version, reducing version data redundancy, ensuring data security and consistentThe distributing integrated CAD system is based-on heterogeneous distributed environment. To adapt distributed process, the expensive EDBMS has a client/server architecture. In this architecture, the data distribution strategy and server model are introduced. The EDBMS and EDB is allowed...
Keywords/Search Tags:Engineering database, database design, version management, CSCW, Distributed database, concurrent control, Client/Server architecture, Agent
PDF Full Text Request
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