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Claudio De Lima - One of the best experts on this subject based on the ideXlab platform.
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Projeto lógico de bancos de dados NOSQL documento a partir de esquemas conceituais entidade-relacionamento estendido (EER)
2016Co-Authors: Claudio De LimaAbstract:Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Ciência da Computação, Florianópolis, 2016O movimento denominado NoSQL surge como tendência para solucionar os desafios inerentes às necessidades atuais de gerenciamento de dados na nuvem, como o tratamento de grandes volumes de dados, a escalabilidade horizontal e o suporte a modelos flexíveis de armazenamento de dados. A organização dos dados em BDs NoSQL requer significativas decisões de projeto, uma vez que afetam requisitos como escalabilidade, desempenho e consistência. Embora BDs NoSQL não requeiram um esquema padrão associado aos dados, eles são categorizados por modelos de dados. O presente trabalho está inserido nesta problemática e propõe uma abordagem para projeto lógico de BDs NoSQL que seguem o modelo de dados de documento. Este modelo é flexível quanto ao suporte a dados e apropriado para aplicações Web, e a abordagem define processos que convertem modelagens conceituais para representações lógicas adequadas e eficientes, para fins de manipulação correta, armazenamento e acesso a dados na nuvem. A proposta é constituída por regras de conversão capazes de transformar cada um dos construtores do modelo conceitual Entidade-Relacionamento Estendido (EER) em uma representação lógica para BDs NoSQL da categoria documento. Um processo de conversão EER-NoSQL automático é proposto, com a finalidade de ordenar a aplicação das regras na produção de um esquema NoSQL documento que tenta evitar a redundância de dados e, ao mesmo tempo, procura gerar uma representação bem estruturada das informações modeladas pelo projeto conceitual. A consideração de informações relativas à principal carga estimada para o BD que está sendo modelado produz esquemas NoSQL documento otimizados. O estudo de caso apresentado demonstra o ganho obtido por documentos conformados a estes esquemas, no tempo de ocupação diário do sistema, para a execução das operações mais frequentes do BD.Abstract: The movement called NoSQL comes as a tendency to address the challenges related to the management of data in the cloud, like the processing of large volumes of data, the horizontal scalability and the support for flexible forms of data storage. Data organization on NoSQL databases (DBs) requires significant design decisions, since they affect requirements such as scalability, performance and consistency. Although NoSQL DBs do not require a Default Schema associated with the data, they are categorized by data models. This work addresses this problem by proposing an approach for the logical design of NoSQL document DBs that follows the document data model. This data model is flexible in terms of data support and suitable for Web applications, and the approach defines processes that convert a conceptual modeling for proper and efficient logical representations aiming at the correct handling, storage and access to data in the cloud. Out proposal consists of conversion rules that transform each one of the concepts of the Extended Entity-Relationship (EER) conceptual model to a logical representation in a NoSQL DB of the document category. An automatic conversion process EER-NoSQL is proposed with the purpose to order the execution of the rules for generating a NoSQL document Schema that tries to avoid data redundancy and, at the same time, tries to generate a well-structured representation of the conceptual Schema information. Additionally, our methodology considers the information workload for the DB being modeled in order to produce an optimized NoSQL document Schema. A case study presented in this work shows the efficiency improvement obtained, in terms of accessing time, for documents that respects the generated logical Schemas, on considering the frequent DB operations
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a workload driven logical design approach for nosql document databases
Information Integration and Web-based Applications & Services, 2015Co-Authors: Claudio De Lima, Ronaldo Dos Santos MelloAbstract:NoSQL databases are designed to manage large volumes of data. Although they do not require a Default Schema associated with the data, they are categorized by data models. Because of this, data organization in NoSQL databases needs significant design decisions because they affect quality requirements such as scalability, consistency and performance. In traditional database design, on the logical modeling phase, a conceptual Schema is transformed into a Schema with lower abstraction and suitable to the target database data model. In this context, the contribution of this paper is an approach for logical design of NoSQL document databases. Our approach consists in a process that converts a conceptual modeling into efficient logical representations for a NoSQL document database. Workload information is considered to determine an optimized logical Schema, providing a better access performance for the application. We evaluate our approach through a case study in the e-commerce domain and demonstrate that the NoSQL logical structure generated by our approach reduces the amount of items accessed by the application queries.
Ronaldo Dos Santos Mello - One of the best experts on this subject based on the ideXlab platform.
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a workload driven logical design approach for nosql document databases
Information Integration and Web-based Applications & Services, 2015Co-Authors: Claudio De Lima, Ronaldo Dos Santos MelloAbstract:NoSQL databases are designed to manage large volumes of data. Although they do not require a Default Schema associated with the data, they are categorized by data models. Because of this, data organization in NoSQL databases needs significant design decisions because they affect quality requirements such as scalability, consistency and performance. In traditional database design, on the logical modeling phase, a conceptual Schema is transformed into a Schema with lower abstraction and suitable to the target database data model. In this context, the contribution of this paper is an approach for logical design of NoSQL document databases. Our approach consists in a process that converts a conceptual modeling into efficient logical representations for a NoSQL document database. Workload information is considered to determine an optimized logical Schema, providing a better access performance for the application. We evaluate our approach through a case study in the e-commerce domain and demonstrate that the NoSQL logical structure generated by our approach reduces the amount of items accessed by the application queries.
Vacca Mario - One of the best experts on this subject based on the ideXlab platform.
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Notes on View Synchronization using Default Logic
Seneca, 2009Co-Authors: Polese Giuseppe, Vacca MarioAbstract:The synchronization of views is one of the Schema evolution problems and it calls for the redefinition of those views becoming undefined after a Schema change, in order to keep them still working on the new Schema. This problem is particularly difficult for capacity reducing Schema changes, when it could be only possible to approximate the existing views. Recently, the use of Schema mappings to express Schema changes has allowed both to deal with a wide range of Schema change operations and to facilitate the view synchronization; but approximating views requires mappings able to describe approximate Schema changes. This paper introduces the Default Schema mappings, a new kind of mappings based on Default logic and it provides a preliminary study showing the possibility of using them to realize an approximate view synchronization process
Bob Nealjoslin - One of the best experts on this subject based on the ideXlab platform.
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a configuration profile Schema for lightweight directory access protocol ldap based agents
RFC, 2007Co-Authors: Morteza Ansari, Luke Howard, Bob NealjoslinAbstract:This document consists of two primary components, a Schema for agents that make use of the Lightweight Directory Access protocol (LDAP) and a proposed use case of that Schema, for distributed configuration of similar directory user agents. A set of attribute types and an object class are proposed. In the proposed use case, directory user agents (DUAs) can use this Schema to determine directory data location and access parameters for specific services they support. In addition, in the proposed use case, attribute and object class mapping allows DUAs to reconfigure their expected (Default) Schema to match that of the end user's environment. This document is intended to be a skeleton for future documents that describe configuration of specific DUA services. This memo provides information for the Internet community.
Polese Giuseppe - One of the best experts on this subject based on the ideXlab platform.
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Notes on View Synchronization using Default Logic
Seneca, 2009Co-Authors: Polese Giuseppe, Vacca MarioAbstract:The synchronization of views is one of the Schema evolution problems and it calls for the redefinition of those views becoming undefined after a Schema change, in order to keep them still working on the new Schema. This problem is particularly difficult for capacity reducing Schema changes, when it could be only possible to approximate the existing views. Recently, the use of Schema mappings to express Schema changes has allowed both to deal with a wide range of Schema change operations and to facilitate the view synchronization; but approximating views requires mappings able to describe approximate Schema changes. This paper introduces the Default Schema mappings, a new kind of mappings based on Default logic and it provides a preliminary study showing the possibility of using them to realize an approximate view synchronization process
