Modeling an engineering design application using extended object-oriented concepts

This paper presents an approach to extend object-oriented data models, in which versions of an object are allowed to appear at different levels of an inheritance hierarchy, in contrast to the known approaches where they are admitted only at one leveI. This approach allows the design and instantiation of objects to beco me very natural, starting with the design of an object in a class and refining it, adding properties to the subclasses. Versions of objects can be defined in a subclass, having ascendant versions/objects associated to the superclasses. The paper also discusses how the extended model can be used to model engineering applications, fulfilling their requirements. The application is the STAR frarnework, which implements an innovative and flexible data model that allows the user to define an object schema for each design object. Design alternatives and views can be created during the design process and are represented in the object schema. Versioning appears in the STAR model not only for the real design data, but also for alternatives and views in the object schema. This requirement is not naturally modeled by the existing version models in object-oriented databases

Versions and configurations in object-oriented database systems : a uniform treatment

Object-oriented database models usually allow versions only at the most specialized type/c1ass in an inheritance hierarchy. The possibility of having versions at different levels of abstraction provides a richer model and allows a more natural representation of the reality. The presence of objects and its corresponding sets of versions at different levels of a type/class hierarchy introduces the need for handling version mappings. Integrity constraints can be associated to these mappings, restricting the set of possible combinations of versions appearing at different levels of the hierarchy. Sets of versions associated with each levei of an object hierarchy often represent a very large set of possible configurations for that object, which is difficult to be handled directly by the user. In this context, adequate mechanisms are very important to define and build object configurations by means of selections applied to the set of all possible configurations, defined by the combinations of versions. This paper proposes an approach in which versions and configurations may appear at different levels of an inheritance hierarchy, and a uniform treatment is given to these two concepts

A database model for object dynamics.

Object-oriented database systems, Dynamic object re-classification, Object role model, Dynamic class hierarchy, Object migration

A temporal versioned object-oriented data schema model

AbstractThis paper describes in a formal way a data schema model which introduces temporal and versioning schema features in an object-oriented environment. In our model, the schema is time dependent and the history of the changes which occur on its elements are kept into version hierarchies. A fundamental assumption behind our approach is that a new schema specification should not define a new database, so that previous schema definitions are considered as alternative design specifications, and consequently, existing data can be accessed in a consistent way using any of the defined schemas

Uma abordagem multi-nivel para suporte a versoes em bancos de dados orientados a objetos

O uso de Sistemas de Bancos de Dados em aplicações não convencionais evidenciou requisitos não atendidos pelos sistemas tradicionais, motivando pesquisas em torno do Paradigma da Orientação a Objetos. Destaca-se o requisito de liberação do número de possíveis instâncias associadas a um mesmo objeto, para a representação do histórico de um objeto, ou para um tratamento flexível da evolução de esquemas, ou, ainda, para manutenção da consistência dos dados em utilização concorrente. Esta liberação conduziu ao conceito de versão. Este trabalho apresenta uma análise do conceito de versão frente aos demais conceitos já incorporados ao paradigma de orientação a objetos, discutindo a necessidade dos novos conceitos. São consideradas as relações entre versões, bem como os condicionamentos impostos pelas hierarquias de classes e tipos sobre as versões de objetos ascendentes ,e descendentes. É proposta uma arquitetura na qual é admitido o versionamento de objetos em qualquer nível da hierarquia de herança, em contraposição aos modelos que admitem apenas o versionamento nas folhas da hierarquia. É mostrado como o modelo proposto descreve com mais propriedade várias situações encontradas em aplicações.The use of Database Management Systems to support non conventional applications put in evidence a set of requirements not supported by the traditional database systerns, and strongly motivated research work towards object oriented database systems. In this context, it was evident the need to liberate the number of instances associated to one database object, to represent the history of the object, to gain flexibility in schema evolution, ar to maintain data consistency, in concurrent access environments, originating the version concept. This work presents an analysis of the version concept, when integrated with the already incorporated concepts of the object-oriented paradigm and discusses the need for new concepts. Aspects considered include: relationships between versions, as well as the conditions imposed by the class and type hierarchies over the versioning of objects and its ascendants and descendants. A multi-Ievel architecture is proposed, which allows versioned objects to appear in any levei of a type ar class hierarchy. This approach is compared with the traditional one, in which versions appear only at the leaves of the hierarchies. It is shown how the proposed architecture allows modeling of many situations of real world applications in a more natural way

A Unifying Version Model for Objects and Schema in Object-Oriented Database System

There have been a number of different versioning models proposed. The research in this area can be divided into two categories: object versioning and schema versioning. In this dissertation, both problem domains are considered as a single unit. This dissertation describes a unifying version model (UVM) for maintaining changes to both objects and schema. UVM handles schema versioning operations by using object versioning techniques. The result is that the UVM allows the OODBMS to be much smaller than previous systems. Also, programmers need know only one set of versioning operations; thus, reducing the learning time by half. This dissertation shows that UVM is a simple but semantically sound and powerful version model for both objects and schema

Grafos versionables: un soporte para el manejo de la evolución del esquema de una BDOO y para el manejo de versiones de un hipertexto

Presentamos en el informe los conceptos básicos sobre Bases de Datos Orientadas a Objetos (BDOO), Bases de Datos Orientadas a Objetos para CAD, Hipertextos y Versiones. Describimos el modelo general, desarrollado para soportar el manejo de versiones y motivado por los requerimientos de las áreas antes mencionadas. Presentamos un prototipo que captura las características fundamentales del modelo. Mostramos la generalidad del modelo y planteamos posibles extensiones al prototipo al utilizar grafos versionables como un soporte para: * la evolución del esquema de una BDOO * la evolución del esquema de una BDOO extendido para soportar objetos compuestos * la evolución en el tiempo de un hipertexto Finalmente, extendemos el prototipo y lo especializamos para soportar versiones de hipertextos.Tesis digitalizada en SEDICI gracias a la colaboración de la Biblioteca de la Facultad de Informática.Facultad de Ciencias Exacta

Grafos versionables: un soporte para el manejo de la evolución del esquema de una BDOO y para el manejo de versiones de un hipertexto

Presentamos en el informe los conceptos básicos sobre Bases de Datos Orientadas a Objetos (BDOO), Bases de Datos Orientadas a Objetos para CAD, Hipertextos y Versiones. Describimos el modelo general, desarrollado para soportar el manejo de versiones y motivado por los requerimientos de las áreas antes mencionadas. Presentamos un prototipo que captura las características fundamentales del modelo. Mostramos la generalidad del modelo y planteamos posibles extensiones al prototipo al utilizar grafos versionables como un soporte para: * la evolución del esquema de una BDOO * la evolución del esquema de una BDOO extendido para soportar objetos compuestos * la evolución en el tiempo de un hipertexto Finalmente, extendemos el prototipo y lo especializamos para soportar versiones de hipertextos.Tesis digitalizada en SEDICI gracias a la colaboración de la Biblioteca de la Facultad de Informática.Facultad de Ciencias Exacta

Tratamento de versões em bancos de dados para sistema de informações geograficas

Orientador: Claudia M. Bauzer MedeirosDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Sistemas de Informação têm introduzido modelos e mecanismos de versões para a manutenção de múltiplos estados ou variações das entidades modeladas. As aplicações fundamentais de versões estão associadas à manutenção de alternativas de projetos em sistemas CAD / CASE e na representação histórica de entidades em sistemas temporais. Esta dissertação apresenta um estudo sobre as aplicações de versões em SIG enfatizando aspectos relativos a aplicações temporais, manipulação de múltiplas representações para as entidades espaciais modeladas e facilidades para manutenção de alternativas de projeto espacial. Os principais resultados são: a proposta de um modelo e mecanismo de versões com recursos básicos para dar apoio a estas aplicações; e uma proposta de extensão a um SGBDOO padrão para permitir a inclusão dos recursos do modeloAbstract: Information systems contemplate version models and mechanisms for the management of multiple states of modeled entities. Versions are associated, mainly, to the management of alternatives in CAD /CASE systems and the representation of historical evolution of entities in temporal systems. This dissertation studies the use of versions in Geographic 1nformation Systems (GIS). The focus of this work is on temporal applications, multiple representations of spatial entities, and the management of alternatives of spatial design. The main results presented are: a model and a mechanism for versions in order to support geographic applications; and the proposal of an extension to a standard OODBMS to support the modelMestradoMestre em Ciência da Computaçã

Delta-based Storage and Querying for Versioned Datasets

Data-driven methods and products are becoming increasingly common in a variety of communities, leading to a huge diversity of datasets being continuously generated, modified, and analyzed. An increasingly important consideration for the underlying data management systems is that, all of these datasets and their versions over time need to be stored and queried for a variety of reasons including, but not limited to, reproducibility, collaboration, provenance, auditing, introspective analysis, and backups. However, most solutions today resort to highly ad hoc and manual version management and sharing techniques, that leads to friction when managing collaborative data science workflows, while also introducing inefficiencies. In this dissertation, we introduce a framework for dataset version management, and address the systems building, operator design, and optimization challenges involved in building a dataset version control system. We describe the various challenges and solutions in the context of our system, called DEX, that we have developed to support increasingly complex version management tasks. We show how to use delta-encoding, a key component in managing redundancy, to provide efficient storage and retrieval for the thousands of dataset versions, and develop a formalism to understand the various trade-offs in a principled manner. We study the storage--recreation trade-off in detail and provide a suite of inexpensive heuristics to obtain high-quality solutions under different settings. In order to provide a rich interface to specify version management tasks, we design a new query language, called VQUEL, with the ability to query dataset versions and provenance in a unified manner. We study how assumptions on the delta format can help in the design of a logical algebra, which we then use to execute increasingly complex queries efficiently. A key characteristic of our query execution methods is that the computational cost is primarily dependent on the size and the number of deltas in the expression (typically small), and not the input dataset versions (which can be very large). Finally, we demonstrate the effectiveness of our developed techniques by extensive evaluation of DEX on a mixture of real-world and synthetic datasets