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Arquitetura de um sistema para integração de bancos de dados com suporte a replicação utilizando tecnologia de grades computacionais.; A resource monitoring and parallel application cooperative scheduling environment on computing grids.

Brito, Mathias Santos de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 09/02/2009 PT
Relevância na Pesquisa
46.28%
Grades computacionais tem a finalidade de oferecer meios para o compartilhamento de recursos distribuídos geograficamente para o uso em aplicações que necessitem. A integração de Bancos de Dados distribuídos geograficamente pode ser obtida através do compartilhamento de recursos provido pela tecnologia de grades. Este trabalho utiliza middlewares de grade computacional, especificamente Globus e OGSA-DAI bem como outras tecnologias como LDAP e JDBC, especificando uma arquitetura distribuída para possibilitar a integração de Bancos de Dados, oferecendo também suporte a replicação. A arquitetura proposta possibilita a configuração de níveis hierárquicos de replicação. O presente trabalho apresenta a implementação de um protótipo desta arquitetura. Um driver JDBC é apresentado para possibilitar o uso dos bancos de dados expostos na grade. Tem-se como resultado deste trabalho, a definição da arquitetura e o desenvolvimento de ferramentas culminando em um protótipo funcional, bem como uma versão estável do driver JDBC. A possibilidade de integração de bancos de dados na grade com suporte a replicação, torna possível aplicações de alto desempenho e alta disponibilidade sem comprometer a autonomia local dos bancos de dados integrados.; Grid Computing have the goal of providing means to share resources to be used by applications that need these resources. The integration of geographically distributed databases can be obtained by sharing resources using grid computing technology. This work uses grid middlewares...

Integração de bancos de dados heterogêneos utilizando grades computacionais.; Heterogeneous databases integration using grid computing.

Kakugawa, Fernando Ryoji
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 18/11/2010 PT
Relevância na Pesquisa
56.33%
Bancos de dados normalmente são projetados para atender a um domínio específico de uma aplicação, tornando o acesso aos dados limitado e uma tarefa árdua em relação à integração de bancos e compartilhamento de dados. Existem várias pesquisas no intuito de integrar dados, como a criação de softwares específicos para uma determinada aplicação e até soluções mais radicais como refazer todos os bancos de dados envolvidos, demonstrando que ainda existem questões em aberto e que a área está longe de atingir soluções definitivas. Este trabalho apresenta conceitos e estratégias para a integração de bancos de dados heterogêneos e a implementa na forma do DIGE, uma ferramenta para desenvolver sistemas de banco de dados integrando diferentes bancos de dados relacionais heterogêneos utilizando grades computacionais. O sistema criado permite o compartilhamento de acesso deixando os dados armazenados em seu local de origem, desta forma, usuários do sistema acessam os dados em outras instituições com a impressão de que os dados estão armazenados localmente. O programador da aplicação final pode acessar e manipular os dados de forma convencional utilizando a linguagem SQL sem se preocupar com a localização e o esquema de cada banco e o administrador do sistema pode adicionar ou remover bancos de forma facilitada sem a necessidade de solicitar alterações na aplicação final.; Databases are usually designed to support a specific application domain...

Compartilhamento de objetos compostos entre bases de dados orientadas a objetos; Sharing composite objects in object-oriented databases

Ferreira, João Eduardo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 05/07/1996 PT
Relevância na Pesquisa
46.11%
Este trabalho apresenta uma proposta para o compartilhamento de dados entre bases de dados orientadas a objetos, em ambientes de desenvolvimento de projetos. O processo de compartilhamento e realizado através de três fases: separação, evolução e integração de dados. Esta forma de compartilhamento atua através de vínculos entre os objetos de base original com a base produto. Foram definidos seis tipos de vínculos, que são estabelecidos no processo de separação: apenas leitura, isolado, flagrante, mutuamente exclusivo, independente e on-line. Com isso, ambas as bases, respeitando as limitações impostas pelo tipo de vinculo entre as mesmas, podem evoluir separadamente e depois de um determinado tempo realizarem, se conveniente, um processo de reintegração. O processo de compartilhamento de dados tem por unidade de gerenciamento os objetos, compostos de base de dados. Os conceitos apresentados podem ser universalmente aplicados, em qualquer base de dados que efetue gerenciamento sobre a composição de seus objetos. Neste trabalho os conceitos de compartilhamento de dados são exemplificados através do modelo de dados SIRIUS.; This work presents a technique to share data stored in an object-oriented databases aimed at design environments. Three process enable the sharing of data between databases: separation...

Architecture for peer-to-peer databases with routing queries using ant colony algorithm and semantic support

Valêncio, Carlos Roberto; Costa, Leandro Rincon; Neto, Paulo Scarpelini; Cansian, Adriano Mauro
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência Formato: 263-268
ENG
Relevância na Pesquisa
46.28%
In a peer-to-peer network, the nodes interact with each other by sharing resources, services and information. Many applications have been developed using such networks, being a class of such applications are peer-to-peer databases. The peer-to-peer databases systems allow the sharing of unstructured data, being able to integrate data from several sources, without the need of large investments, because they are used existing repositories. However, the high flexibility and dynamicity of networks the network, as well as the absence of a centralized management of information, becomes complex the process of locating information among various participants in the network. In this context, this paper presents original contributions by a proposed architecture for a routing system that uses the Ant Colony algorithm to optimize the search for desired information supported by ontologies to add semantics to shared data, enabling integration among heterogeneous databases and the while seeking to reduce the message traffic on the network without causing losses in the amount of responses, confirmed by the improve of 22.5% in this amount. © 2011 IEEE.

Evaluating certification protocols in the partial database state machine

Sousa, António Luís Pinto Ferreira de; Moura, Francisco Coelho Soares; Pereira, José, 1973-; Oliveira, Rui Carlos Mendes de; Correia Júnior, Alfrânio Tavares
Fonte: IEEE Computer Society Publicador: IEEE Computer Society
Tipo: Conferência ou Objeto de Conferência
Publicado em //2006 ENG
Relevância na Pesquisa
46.05%
Partial replication is an alluring technique to ensure the reliability of very large and geographically distributed databases while, at the same time, offering good performance. By correctly exploiting access locality most transactions become confined to a small subset of the database replicas thus reducing processing, storage access and communication overhead associated with replication. The advantages of partial replication have however to be weighted against the added complexity that is required to manage it. In fact, if the chosen replica configuration prevents the local execution of transactions or if the overhead of consistency protocols offsets the savings of locality, potential gains cannot be realized. These issues are heavily dependent on the application used for evaluation and render simplistic benchmarks useless. In this paper, we present a detailed analysis of Partial Database State Machine (PDBSM) replication by comparing alternative partial replication protocols with full replication. This is done using a realistic scenario based on a detailed network simulator and access patterns from an industry standard database benchmark. The results obtained allow us to identify the best configuration for typical on-line transaction processing applications.; União Europeia - GORDA Project (FP6-IST/004758).

Partial replication in distributed software transactional memory

Silva, João André Almeida e
Fonte: Faculdade de Ciências e Tecnologia Publicador: Faculdade de Ciências e Tecnologia
Tipo: Dissertação de Mestrado
Publicado em //2013 ENG
Relevância na Pesquisa
46.03%
Dissertação para obtenção do Grau de Mestre em Engenharia Informática; Distributed software transactional memory (DSTM) is emerging as an interesting alternative for distributed concurrency control. Usually, DSTM systems resort to data distribution and full replication techniques in order to provide scalability and fault tolerance. Nevertheless, distribution does not provide support for fault tolerance and full replication limits the system’s total storage capacity. In this context, partial data replication rises as an intermediate solution that combines the best of the previous two trying to mitigate their disadvantages. This strategy has been explored by the distributed databases research field, but has been little addressed in the context of transactional memory and, to the best of our knowledge, it has never before been incorporated into a DSTM system for a general-purpose programming language. Thus, we defend the claim that it is possible to combine both full and partial data replication in such systems. Accordingly, we developed a prototype of a DSTM system combining full and partial data replication for Java programs. We built from an existent DSTM framework and extended it with support for partial data replication. With the proposed framework...

Privacy-preserving tuple matching in distributed databases

Sang, Y.; Shen, H.; Tian, H.
Fonte: IEEE Computer Soc Publicador: IEEE Computer Soc
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
Relevância na Pesquisa
46.05%
We address the problems of Privacy-Preserving Duplicate Tuple Matching (PPDTM) and Privacy-Preserving Threshold Attributes Matching (PPTAM) in the scenario of a horizontally partitioned database among N parties, where each party holds a private share of the database’s tuples and all tuples have the same set of attributes. In PPDTM, each party determines whether its tuples have any duplicate on other parties’ private databases. In PPTAM, each party determines whether all attribute values of each tuple appear at least a threshold number of times in the attribute unions. We propose protocols for the two problems using additive homomorphic cryptosystem based on the subgroup membership assumption, e.g., Paillier’s and ElGamal’s schemes. By analysis on the total numbers of modular exponentiations, modular multiplications and communication bits, with a reduced computation cost which dominates the total cost, by trading off communication cost, our PPDTM protocol for the semihonest model is superior to the solution derivable from existing techniques in total cost. Our PPTAM protocol is superior in both computation and communication costs. The efficiency improvements are achieved mainly by using random numbers instead of random polynomials as existing techniques for perturbation...

Network application server using Extensible Mark-up Language (XML) to support distributed databases and 3D environments

Williams, Clifton James
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
Relevância na Pesquisa
46.05%
This thesis contributes to the US Navy forces maintaining information superiority in a Network Centric Warfare environment. This research develops an Extensible Markup Language XML-based Web Publishing Framework, which supports the Web Enabled Navy (WEN) architecture infrastructure. The Web application framework easily supports connections to multiple distributed databases and XML-based presentations, specifically three-dimensional (3D) simulations utilizing Extensible 3D (X3D) and Virtual Reality Modeling Language (VRML). This research evaluates and demonstrates the functionality of an XML-based Web Publishing Framework. The research demonstrates ability to connect to both XML and non-XML heterogeneous database systems and provides a framework for the distribution data across heterogeneous systems. The system supports usage in multi-tier network architecture. 3D modeling and simulations provide insights into operations that cannot be realized using standard two-dimensional (2D) renditions. The development of an application server to support 3D modeling and simulations for operational planning will provide the U.S. Navy a better way of realizing operational limits. This research addresses the Web publishing framework, which supports the development XML based data exchange...

Monitoring and analysis of queries in distributed databases; Monitorização e análise de interrogações em bases de dados distribuídas

Guimarães, Pedro Miguel Pimentel
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Dissertação de Mestrado
Publicado em 07/01/2015 ENG
Relevância na Pesquisa
56.24%
Dissertação de Mestrado em Engenharia Informática; Scalable database services combining multiple technologies, including SQL and NoSQL, are increasingly in vogue. In this context, the CoherentPaaS research project aims at providing an integrated platform with multiple data management technologies, united by a common query language and global transactional coherence. For this integration to succeed, it must provide the same monitoring capabilities of tra ditional relational databases, namely, for database administrators to optimise its operation. However, achieving this in a distributed and heterogeneous system is in itself a challenge. This work proposes a solution to this problem with X-Ray, that allows monitoring code to be added to a Java-based distributed system by manipulating its bytecode at runtime. The resulting information is collected in a NoSQL database and then processed and visualised graphically. This system is evaluated experimentally by adding monitoring to Apache Derby and tested with the standard TPC-C benchmark workload.; Os serviços escaláveis de base de dados combinando diversas tecnologias, incluindo SQL e NoSQL, estão cada vez mais em voga. Neste contexto, o projeto de investigação Coherent PaaS tem como objetivo oferecer uma plataforma integradora de múltiplas tecnologias de gestão de dados...

Heterogeneous Relational Databases for a Grid-enabled Analysis Environment

Ali, Arshad; Anjum, Ashiq; Azim, Tahir; Bunn, Julian; Iqbal, Saima; McClatchey, Richard; Newman, Harvey; Shah, S. Yousaf; Solomonides, Tony; Steenberg, Conrad; Thomas, Michael; van Lingen, Frank; Willers, Ian
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/04/2005
Relevância na Pesquisa
36.38%
Grid based systems require a database access mechanism that can provide seamless homogeneous access to the requested data through a virtual data access system, i.e. a system which can take care of tracking the data that is stored in geographically distributed heterogeneous databases. This system should provide an integrated view of the data that is stored in the different repositories by using a virtual data access mechanism, i.e. a mechanism which can hide the heterogeneity of the backend databases from the client applications. This paper focuses on accessing data stored in disparate relational databases through a web service interface, and exploits the features of a Data Warehouse and Data Marts. We present a middleware that enables applications to access data stored in geographically distributed relational databases without being aware of their physical locations and underlying schema. A web service interface is provided to enable applications to access this middleware in a language and platform independent way. A prototype implementation was created based on Clarens [4], Unity [7] and POOL [8]. This ability to access the data stored in the distributed relational databases transparently is likely to be a very powerful one for Grid users...

A Taxonomy of Data Grids for Distributed Data Sharing, Management and Processing

Venugopal, Srikumar; Buyya, Rajkumar; Ramamohanarao, Kotagiri
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/06/2005
Relevância na Pesquisa
46%
Data Grids have been adopted as the platform for scientific communities that need to share, access, transport, process and manage large data collections distributed worldwide. They combine high-end computing technologies with high-performance networking and wide-area storage management techniques. In this paper, we discuss the key concepts behind Data Grids and compare them with other data sharing and distribution paradigms such as content delivery networks, peer-to-peer networks and distributed databases. We then provide comprehensive taxonomies that cover various aspects of architecture, data transportation, data replication and resource allocation and scheduling. Finally, we map the proposed taxonomy to various Data Grid systems not only to validate the taxonomy but also to identify areas for future exploration. Through this taxonomy, we aim to categorise existing systems to better understand their goals and their methodology. This would help evaluate their applicability for solving similar problems. This taxonomy also provides a "gap analysis" of this area through which researchers can potentially identify new issues for investigation. Finally, we hope that the proposed taxonomy and mapping also helps to provide an easy way for new practitioners to understand this complex area of research.; Comment: 46 pages...

Providing an Object Allocation Algorithm in Distributed Databases Using Efficient Factors

Delavar, Arash Ghorbannia; Keshani, Golnoosh
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 05/10/2012
Relevância na Pesquisa
46.21%
Data replication is a common method used to improve the performance of data access in distributed database systems. In this paper, we present an object replication algorithm in distributed database systems (ORAD). We optimize the created replicated data in distributed database systems by using activity functions of previous algorithms, changing them with new technical ways and applying ORAD algorithm for making decisions. We propose ORAD algorithm with using effective factors and observe its results in several valid situations. Our objective is to propose an optimum method that replies read and write requests with less cost in distributed database systems. Finally, we implement ORAD and ADRW algorithms in a PC based network system and demonstrate that ORAD algorithm is superior to ADRW algorithm in the field of average request servicing cost.; Comment: IJCSI International Journal of Computer Science Issues, Vol. 9, Issue 4, No 3, 2012

Using Object-Relational Mapping to Create the Distributed Databases in a Hybrid Cloud Infrastructure

Lukyanchikov, Oleg; Pluzhnik, Evgeniy; Payain, Simon; Nikulchev, Evgeny
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 04/01/2015
Relevância na Pesquisa
46.13%
One of the challenges currently problems in the use of cloud services is the task of designing of specialized data management systems. This is especially important for hybrid systems in which the data are located in public and private clouds. Implementation monitoring functions querying, scheduling and processing software must be properly implemented and is an integral part of the system. To provide these functions is proposed to use an object-relational mapping (ORM). The article devoted to presenting the approach of designing databases for information systems hosted in a hybrid cloud infrastructure. It also provides an example of the development of ORM library.

Intelligent Implementation Processor Design for Oracle Distributed Databases System

Hassen, Fadoua; Touzi, Amel Grissa
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/04/2015
Relevância na Pesquisa
56.2%
Despite the increasing need for modeling and implementing Distributed Databases (DDB), distributed database management systems are still quite far from helping the designer to directly implement its BDD. Indeed, the fundamental principle of implementation of a DDB is to make the database appear as a centralized database, providing series of transparencies, something that is not provided directly by the current DDBMS. We focus in this work on Oracle DBMS which, despite its market dominance, offers only a few logical mechanisms to implement distribution. To remedy this problem, we propose a new architecture of DDBMS Oracle. The idea is based on extending it by an intelligent layer that provides: 1) creation of different types of fragmentation through a GUI for defining different sites geographically dispersed 2) allocation and replication of DB. The system must automatically generate SQL scripts for each site of the original configuration.

Consistent Checkpointing in Distributed Databases: Towards a Formal Approach

Baldoni, R.; Quaglia, F.; Raynal, M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 22/10/1999
Relevância na Pesquisa
46.11%
Whether it is for audit or for recovery purposes, data checkpointing is an important problem of distributed database systems. Actually, transactions establish dependence relations on data checkpoints taken by data object managers. So, given an arbitrary set of data checkpoints (including at least a single data checkpoint from a data manager, and at most a data checkpoint from each data manager), an important question is the following one: Can these data checkpoints be members of a same consistent global checkpoint?''. This paper answers this question by providing a necessary and sufficient condition suited for database systems. Moreover, to show the usefulness of this condition, two {\em non-intrusive} data checkpointing protocols are derived from this condition. It is also interesting to note that this paper, by exhibiting correspondences'', establishes a bridge between the data object/transaction model and the process/message-passing model.; Comment: 13 pages, 3 figures

Distributed Kernel Regression: An Algorithm for Training Collaboratively

Predd, Joel B.; Kulkarni, Sanjeev R.; Poor, H. Vincent
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 20/01/2006
Relevância na Pesquisa
46.05%
This paper addresses the problem of distributed learning under communication constraints, motivated by distributed signal processing in wireless sensor networks and data mining with distributed databases. After formalizing a general model for distributed learning, an algorithm for collaboratively training regularized kernel least-squares regression estimators is derived. Noting that the algorithm can be viewed as an application of successive orthogonal projection algorithms, its convergence properties are investigated and the statistical behavior of the estimator is discussed in a simplified theoretical setting.; Comment: To be presented at the 2006 IEEE Information Theory Workshop, Punta del Este, Uruguay, March 13-17, 2006

Review on Fragment Allocation by using Clustering Technique in Distributed Database System

Dash, Priyanka; Rout, Ranjita; Pratihari, Satya Bhusan; Padhi, Sanjay Kumar
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 04/10/2013
Relevância na Pesquisa
46.21%
Considerable Progress has been made in the last few years in improving the performance of the distributed database systems. The development of Fragment allocation models in Distributed database is becoming difficult due to the complexity of huge number of sites and their communication considerations. Under such conditions, simulation of clustering and data allocation is adequate tools for understanding and evaluating the performance of data allocation in Distributed databases. Clustering sites and fragment allocation are key challenges in Distributed database performance, and are considered to be efficient methods that have a major role in reducing transferred and accessed data during the execution of applications. In this paper a review on Fragment allocation by using Clustering technique is given in Distributed Database System.; Comment: 9 pages,3 figures

Mining The Data From Distributed Database Using An Improved Mining Algorithm

Renjit, J. Arokia; Shunmuganathan, K. L.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 09/04/2010
Relevância na Pesquisa
46.27%
Association rule mining is an active data mining research area and most ARM algorithms cater to a centralized environment. Centralized data mining to discover useful patterns in distributed databases isn't always feasible because merging data sets from different sites incurs huge network communication costs. In this paper, an Improved algorithm based on good performance level for data mining is being proposed. In local sites, it runs the application based on the improved LMatrix algorithm, which is used to calculate local support counts. Local Site also finds a centre site to manage every message exchanged to obtain all globally frequent item sets. It also reduces the time of scan of partition database by using LMatrix which increases the performance of the algorithm. Therefore, the research is to develop a distributed algorithm for geographically distributed data sets that reduces communication costs, superior running efficiency, and stronger scalability than direct application of a sequential algorithm in distributed databases.; Comment: IEEE Publication format, International Journal of Computer Science and Information Security, IJCSIS, Vol. 7 No. 3, March 2010, USA. ISSN 1947 5500, http://sites.google.com/site/ijcsis/

Secure Mining of Association Rules in Horizontally Distributed Databases

Tassa, Tamir
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 25/06/2011
Relevância na Pesquisa
56.27%
We propose a protocol for secure mining of association rules in horizontally distributed databases. The current leading protocol is that of Kantarcioglu and Clifton (TKDE 2004). Our protocol, like theirs, is based on the Fast Distributed Mining (FDM) algorithm of Cheung et al. (PDIS 1996), which is an unsecured distributed version of the Apriori algorithm. The main ingredients in our protocol are two novel secure multi-party algorithms --- one that computes the union of private subsets that each of the interacting players hold, and another that tests the inclusion of an element held by one player in a subset held by another. Our protocol offers enhanced privacy with respect to the protocol of Kantarcioglu and Clifton. In addition, it is simpler and is significantly more efficient in terms of communication rounds, communication cost and computational cost.

A comparative study of concurrency control algorithms for distributed databases

Aparicio, Fabio
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
56.37%
The declining cost of computer hardware and the increasing data processing needs of geographically dispersed organizations have led to substantial interest in distributed data management. These characteristics have led to reconsider the design of centralized databases. Distributed databases have appeared as a result of those considerations. A number of advantages result from having duplicate copies of data in a distributed databases. Some of these advantages are: increased data accesibility, more responsive data access, higher reliability, and load sharing. These and other benefits must be balanced against the additional cost and complexity introduced in doing so. This thesis considers the problem of concurrency control of multiple copy databases. Several synchronization techniques are mentioned and a few algorithms for concurrency control are evaluated and compared.