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Vol: 49(63) No: 3 / September 2004 Objectual Schemas and Derived Classes in the Design of Object–Relational Databases for Mechanical System Sorin Borza University Lucian Blaga of Sibiu, Romania, Faculty of Engineering, , phone: 40-269-217928, e-mail: sorin.borza@ulbsibiu.ro Ionel Jian Department of Computer Science, Politehnica University of Timisoara, Romania, Bd. V. Parvan no. 2, Timisoara, Romania, e-mail: jian@cs.utt.ro Keywords: objectual relational databases, objects, indexes, tables, derived classes, objectual schema Abstract The objectual schema and derived classes are important mechanisms for designing objectual-relational databases. Today the Relational Object Oriented Databases are the most important databases for manufacturing systems. This paper describes how objectual schema is used in design process of relational objectual databases, for mechanical systems. Defining the objectual-relational databases is a process, which tries to maintain the preservation of the relational characteristics of the databases in an objectual medium. That is why the relations defined as classes of a predefined type (cursor) are preserved; the database of relational medium is defined as a class data environment. To this class will be attached types of class objects from relational database. The existing relations between the tables inside the database are defined as predefined type classes named cursor. The views are defined as cursor classes. The concepts of derived class, partial derived class, external schemes etc., will be applied in order to get the object database. A particular approach is the producing of objectual database corresponding to each tool type with the help of specific classes, which aim at generating the source code for each objectual database. References [1] Kanda, T., Mineo, K., New Trend of database for the Internet era – Object database and its application, ISES’01, Wuhn University, martie 2001 [2] Hoffer, Prescott & McFadden, Modern Database Management, 6th Edition, 2002 [3] Rennhackkamp, M., Extending Relational DBMSs, Miller Freeman, Inc., Cape Town, 1997. [4] Jepson, B., Object-Oriented Apps in a Relational Database, CMP Media LLC, 2002. [5] Leawitt, N., Whatever Happened to Obect-Oriented Databases, Lee Garber Inc, Los Alamitos 2000. [6] Borza, S., Object Oriented Databases for Mechanical Systems, Masters degree Thesis, Timisoara 2003. [7] Khoshafian, S., Object Oriented Databases, John Wiley and Sons, 1993. [8] Atkinson, M., Bancilhon, F., DeWitt, D., Dittrick, K., Maier, D., Zdonik, S., The Object Oriented Database System Manifesto, 1989. [9] Abiteboul, S., Kanellakis, P., Object identity as a query language primitive, Proceedings of the 1989 ACM SIGMOD, Portland, Oregon, June 89. [10] Banerjee, J., Chou, H.T., Garza, J., W. Kim, D. Woelk, N.,Ballou, H.J. Kim, Data model issues for object-oriented applications, ACM TOIS, January 1987. [11] Dittrich, K.R. (ed) Advances in Object-Oriented Database Systems, Lecture Notes in Computer Science, Vol, 334, Springer-Verlag, 1988. [12] Bazian, M., Special Edition Using Visual FoxPro TM 6, QUE Corporation 1999. |