Book Chapter10.1007/3-540-44759-8_80
Closed External Schemas in Object-Oriented Databases
Manuel Torres,José Samos +1 more
- 03 Sep 2001
- pp 826-835
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TL;DR: The main benefit of reduction closure is that it can be used as a method to simplify the external schema definition process, because explicit definition of derived classes for hiding external references is avoided.
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Abstract: Schema closure is a property to guarantee that classes in a schema have not references to classes that are not included into it (external references). The existing methodologies solve this point including referenced classes into the schema. In this paper, a new kind of schema closure (reduction closure) is put forward. Reduction closure is based on the transformation of classes with external references, removing these references to fulfil the schema closure property. The main benefit of reduction closure is that it can be used as a method to simplify the external schema definition process, because explicit definition of derived classes for hiding external references is avoided. In addition, the explicit definition of derived classes to update the references to modified classes is also avoided. This closure algorithm is part of an external schema generation system for ODMG databases that we are developing, which is also briefly described in this paper.
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Citations
A View-Based Methodology for Collaborative Ontology Engineering: An Approach for Complex Applications (VIMethCOE)
Ernesto Jiménez-Ruiz,Rafael Berlanga +1 more
- 26 Jun 2006
TL;DR: This paper proposes a view-based methodology for the collaborative, distributed and modular development of large ontology, which achieves the identified requirements for the proper evolution and use of very large ontologies.
12
Closing Ontologies to Define OLAP Systems
Manuel Torres,José Samos,Eladio Garví +2 more
- 01 Oct 2014
TL;DR: Two basic approaches are proposed: enlargement and reduction closure of ontology views in the construction of OLAP On-Line Analytical Processing systems.
3
A Language to Define External Schemas in ODMG Databases
Manuel Torres,José Samos +1 more
TL;DR: An external schema definition methodology that allows the definition of external schemas in ODMG databases is developed and the language used by the schema definer to specify the schema components (e.g. classes, interfaces, and so on) is proposed.
A Methodology to Define External Schemas in ODMG Databases
Manuel Torres,José Samos +1 more
TL;DR: This methodology proposes a solution for the tasks involved---specification, closure and generation of external schemas---introducing also an extension of ODMG metadata to enable the definition of external Schemas in ODMG databases.
2
Closing schemas in object-relational databases
Manuel Torres,José Samos,Eladio Garví +2 more
- 28 Sep 2010
TL;DR: In this work, both closure approaches and the algorithms to carry out the closure in each are described and these algorithms generate and incorporate the needed components to reach the schema closure making easier therefore the definition of external schemas.
1
References
Definition of External Schemas in Object Oriented Databases
José Samos
- 01 Jan 1996
TL;DR: A new external schema definition methodology for object oriented databases (OODB) that solves some of the problems of existing methodologies is presented and offers a way of integrating and reusing different external schema definitions.
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External Schema Generation Algorithms for Object Oriented Databases
José Samos,Fèlix Saltor +1 more
- 01 Jan 1997
TL;DR: In this paper two external schema generaion algorithms are presented, defined in the framework of the new external schema definition methodology for OODBs, that avoid the generation of auxiliary classes that are not included in the defined external schema.
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Generation of external schemas in ODMG databases
Manuel Torres,José Samos +1 more
- 16 Jul 2001
TL;DR: A method for generating external schemas in object oriented databases in the ODMG framework is proposed, which allows the definition of external schema in ODMG.
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Viewpoints in object database systems
Elisa Bertino,Giovanna Guerrini +1 more
- 14 Oct 1996
TL;DR: It is shown how an object-oriented view mechanism can be exploited to allow different applications to see the same database according to different viewpoints.
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Definition of External Schemas in ODMG Databases
Manuel Torres,José Samos +1 more
- 18 Dec 2000
TL;DR: The proposed language is an extension of ODMG ODL and allows the definition of external schemas using the ODMG named queries for defining derived classes, and is independent of the derived classes definition mechanism used.
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