W. Klas, P. Fankhauser, P. Muth, T. Rakow, and E. J. Neuhold. Database Integration using the Open Object-Oriented Database System VODAK. In O. Bukhres and A. K. Elmagarmid, editor, Object Oriented Multidatabase Systems: A Solution for Advanced Applications. Prentice Hall, Englewood Cliffs, N.J., 1996.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....transactional property as our transactional message call. On the side of views, other systems integrating this concept in a general purpose object oriented programming languages has not yet been designed. Views structures are always left in the DBMS or MDBS (see for instance [27] 4] 1] [21]) Moreover, such view systems often do not allow instant bottom up updates or even up bottom updates. Finally, these systems do not propose the ability of dynamically combining many mappings for one view. To sum up, we think that our system, by including and adapting in a general purpose object ....

W. Klas, P. Fankhauser and P. Muth. Database Integration using the open object-oriented system VODAK. In Object Oriented Multidatabase systems, O.A. Bukhres et A. Elmagarmid Ed., Prentice hall, Englewood Cliffs, New Jersey. Pages 472-532. 1996.

....This has the advantage of simplifying schema integration from the integrator s point of view and thereby minimising process errors. ffl The tool should be DBMS and DDL independent, i.e. it should be relatively easy to adapt to a new DBMS and DDL. Many of the available research projects (e.g. [BER96a, BER96b, FAH94, KLA96]) are DBMS and DDL dependent, therefore including a new DBMS in their integration processes will require substantial adaption and re programming work, costing time and money. Even though most of the above projects (for example [KLA96] use a canonical data model, this model is focussed on a ....

....of the available research projects (e.g. BER96a, BER96b, FAH94, KLA96] are DBMS and DDL dependent, therefore including a new DBMS in their integration processes will require substantial adaption and re programming work, costing time and money. Even though most of the above projects (for example [KLA96]) use a canonical data model, this model is focussed on a particular type of DBMS. This means that including a new type of DBMS may require the canonical data model to be altered either by the addition of new data structures or the modification of existing ones. Alteration is necessary to model ....

[Article contains additional citation context not shown here]

W. Klas et al. Database Integration Using the Open Object-Oriented Database System: VODAK. In O. A. Bukhres and A. K. Elmagarmid, editors, Object-Oriented Multidatabase Systems: A Solution for Advanced Applications, pages 251--269. Prentice Hall, 1996.

....can be decomposed and translated, and the local results can be synthesised automatically. 1 Introduction Due to the rapid advance in networking technologies and the requirement of data sharing among different organizations, federated systems have become the trend of future database developments [BOT86, LA86, Jo93, SK92, CW93, HLM94, RPRG94, KFMRN96]. The research on this issue can be roughly divided into two main categories: the tightly integrated approach that integrates databases by building an integrated schema and the loosely integrated approach that achieves interoperability by using a multidatabase language. The method proposed here ....

W. Klas, P. Fankhauser, P. Muth, T. Rakow and E.J. Neuhold. "Database Integration Using the Open Object-oriented Database System VODAK," in: O. Bukhres, A.K. Elmagarmid (eds):Object-oriented Multidatabase Systems: A Solution for Advanced Applications. Chapter 14. Prentice Hall, Englewood Cliffs, N.J., 1996.

....or provided by the other partners within the project (e.g. Whatif, LUDI [2] must be connected to the DBMS. Database Integration There exist several approaches and projects which address interoperability or integration of information bases. For an extensive discussion of related work see [3][11][12] 20] which give good overviews and present fundamental concepts including the terminology of the different approaches, e.g. multidatabase systems, multidatabase languages, and federated database systems. GMD IPSI takes what is called the federated database approach. The tools and techniques ....

Klas, W., Fankhauser, P., Muth, P., Rakow, T.,Neuhold, E.J.: "Database Integration Using the Open Object-oriented Database System VODAK", to appear in: Object-Oriented Multidatabase Systems, Eds. Elmagarmid, A., Bukhres, O., Prentice Hall, 1994.

....survey of the problem of concurrency control in multidatabase systems. We outlined the differences between concurrency control in agent based systems and multidatabases in Section 2.3. Multidatabase systems that offer method based interfaces include the DOM project [17] and the VODAK system [15]. The majority of multidatabase transaction management systems adopt a centralized approach; 29, 1] are possible exceptions. Many researchers have identified the need for advanced transaction models (see [7] for examples) ACTA [5] provides a framework based on first order logic for reasoning ....

W. Klas, P. Fankhauser, P. Muth, T. Rakow, and E. J. Neuhold. Database Integration using the Open ObjectOriented Database System VODAK. In Ahmed Elmagarmid and Omran Bukhres, editors, Object-Oriented Multidatabases. Prentice Hall, 1995.

....are acyclic. 3. Monotonicity of Inheritance. Specialization is preserved along equal attributes relationships. A detailed formalization of ODMG in terms of the concept of schema graph can be found in [2] 2. 2 The schema integration methodology: SIM The schema integration methodology SIM [3, 7] reduces schema integration to the resolution of a set of equivalence vertex path correspondences between (arbitrary) subschemas of the local databases. From such a set of correspondences, SIM semi automaticallyderives schema transformations, called schema augmentations, from each local schema to ....

....in which path correspondences have been stated. For this purpose weintroduce a mechanism to identify those subschemas affected by a new correspondence and re integrate only on them. This permits us to automatically propagate the inclusion as well as the deletion of correspondences. Based on SIM [7], we try to integrate on this new set of correspondences together with the already acquired augmentations. When no conflict arises, SIM resolves them automatically. On the other hand, in case the addition of the new correspondences produces an inconsistency with the already integrated schema, SIM ....

W. Klas, P. Fankhauser, P. Muth, T. Rakow, and E. J. Neuhold. Database Integration using the Open Object-Oriented Database System VODAK. In O. Bukhres and A. K. Elmagarmid, editor, Object Oriented Multidatabase Systems: A Solution for Advanced Applications. Prentice Hall, Englewood Cliffs, N.J., 1996.

....the same languages, many structurally different ways of expressing the same information are possible. The problems of working with multiple databases and schemas have been identified in the literature by names such as interoperability [34] heterogeneous schema integration [19] global schema [31], and view integration [6] All of these methodologies attempt to provide for the application and the users a unified and therefore simplified interface that allows for easier human interpretation and easier automatic processing of a multiplicity of databases. This field has been extensively ....

.... heterogeneous attributes [9] Recent work on integrating object oriented schemas has analyzed the formal properties of integrated schemas with respect to information preservation [39] and extended the transformational expressiveness of rules to cope with more kinds of modeling differences [53, 52, 31, 9]. 2.2. Linguistic Analysis There exists a long research tradition in computer linguistics for the problem of extracting the meaning from free texts. Typical linguistic approaches rely on a syntactical and semantical analysis of the given text source. In the context of information extraction, the ....

Wolfgang Klas, Peter Fankhauser, Peter Muth, Thomas Rakow, and Erich J. Neuhold. Database Integration using the Open Object-Oriented Database System VODAK, chapter 14: Object Oriented Multidatabase Systems: A Solution for Advanced Applications. Prentice Hall, Englewood Cliffs, N.J. (1996).

....transfer of objects. This protocol is used to send, prepare, and execute database programs on remote export schemata. The Local Layer and the Communication Layer give means to realize loosely coupled federations, where data have to be merged explicitly by the application. The Interoperable Layer [22] provides means to specify federated schemata, which support unified access to multiple databases with related data (tightly coupled federations) This layer provides a number of tools to actually interchange data between local databases and to provide new applications with 2nd Intl. East West ....

Wolfgang Klas, Peter Fankhauser, Peter Muth, Thomas C. Rakow, and Erich J. Neuhold. Database Integration using the Open Object-Oriented Database System VODAK. In Omran Bukhres and Ahmed K. Elmagarmid, editors, Object Oriented Multidatabase Systems. Prentice Hall, September 1994. To appear.

....schema and the import schemas. A fully automatic evolution of integrated schemas along changes in the local schemas is impossible. However, by extending the Integrators Workbench, which generates integrated schemas automatically on the basis of correspondences between local schema constituents [16], changes which do not affect or decrease the information capacity of local schemas can be automated too. Changes that increase the information capacity require human assessment in the form of additional schema correspondences. 5.3 Global Objects Identifiers The format chosen for object ....

W. Klas, P. Fankhauser, P. Muth, T. Rakow, E.J. Neuhold, "Database Integration using the Open Object-Oriented Database System VODAK", In O. Bukhres and A. Elmagarimid Ed., Object-Oriented Multibase Systems, A Solution for Advanced Applications, Chap. 14, Prentice Hall, 1996.

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