In parallel databasesystems, data is partitioned and replicated across multiple independent nodes to improve system performance and increase robustness. In current practice of database partitioning design, all replic...
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ISBN:
(纸本)9783319642031;9783319642024
In parallel databasesystems, data is partitioned and replicated across multiple independent nodes to improve system performance and increase robustness. In current practice of database partitioning design, all replicas are uniformly partitioned, however, different statements may prefer contradictory partitioning plans, so a single plan cannot achieve the overall optimal performance for the workload. In this paper, we propose a novel approach of replica-aware data partitioning design to address the contradictions. According to the access graph of SQL statements, we use the k-medoids algorithm to classify workload into statement clusters, then we use the branch-and-bound algorithm to search for the optimal partitioning plan for each cluster. Finally, we organize replicas with these plans, and route statements to their preferred replicas. We use TPC-E, TPC-H and National College and University Enrollment system (NACUES) to evaluate our approach. The evaluation results demonstrate that our approach improves system performance by up to 4x over the current practice of partitioning design.
This paper will examine the underlying features of the distributeddatabase architecture .Learning the task of distributed database management system will lead us to a successful design. The design will improve scalab...
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ISBN:
(纸本)9781424437566
This paper will examine the underlying features of the distributeddatabase architecture .Learning the task of distributed database management system will lead us to a successful design. The design will improve scalability, accessibility and flexibility while accessing various types of data. Developing a successful distributeddatabasesystem requires to address the importance of security issues that may arise and possibly compromise the access control and the integrity of the system. We propose some solutions for some security aspects such as multilevel access control, confidentiality, reliability, integrity and recovery that pertain to a distributeddatabasesystem.
The University of Maryland University College (UMUC) serves a dispersed patron base, and its library has developed, over time, a circulation system for distributing physical research materials to its patrons throughou...
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The adoption of Internet and Intranet technologies has been rapidly spreading in recent years, and existing systems are being replaced with new systems based on these new technologies. At changing environment of the p...
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ISBN:
(纸本)0780375254
The adoption of Internet and Intranet technologies has been rapidly spreading in recent years, and existing systems are being replaced with new systems based on these new technologies. At changing environment of the power system industry, in 1999 Toshiba announced a concept of new middleware for power system network control systems including energy managementsystems(EMS), supervisory control and data acquisition systems(SCADA), and distribution managementsystems (DMS). This new middleware is based on latest Internet and Intranet technologies, offering the real-time operation and high reliability required for network control systems. Presently, several systems are being manufactured, and some of which are already at the stage of commissioning tests. This Paper focuses a SCADA system for the Ultra High Voltage equipment pilot plant of Tokyo Electric Power Corp.(TEPCO) which has been working since December. 2000,and uses Intranet technologies, with an emphasis on a functional overview and the features of the newly developed system.
This paper proposes to apply the Intranet technology to SCADA (Supervisory Control and Data Acquisition system) for power system and presents the result of development of the Intranet-Based SCADA trial system. The Int...
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ISBN:
(纸本)0780359356
This paper proposes to apply the Intranet technology to SCADA (Supervisory Control and Data Acquisition system) for power system and presents the result of development of the Intranet-Based SCADA trial system. The Intranet-Based SCADA is concerned about real-time performance and reliability of supervisory control How the trial system resolved these issues is discussed and various measurements at the trial system including picture display time, supervisory control response time and fail-over time are presented. Real time performance, system cost and maintainability of the Intranet-Based SCADA are evaluated based upon the trail system. And the feature of the Intranet-Based SCADA such as failover between geographically separated servers and capability of supervisory control at night from another control center are discussed. Information security of the Intranet-Based SCADA that should be paid particular attention to is also discussed.
A distributed database management system (DDBMS) manages a collection of data stored at various processing nodes of a computer network. Global queries are processed by DDBMS, and tasks (Join operations in these querie...
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A distributed database management system (DDBMS) manages a collection of data stored at various processing nodes of a computer network. Global queries are processed by DDBMS, and tasks (Join operations in these queries) are assigned to various nodes in the network. Optimal allocation of these tasks are discussed, with reliability as the objective function and communication-cost as the constraint function. A model for reliability-based task allocation is developed. It is converted into a State-Space Search-Tree and is implemented using a branch-and-bound algorithm. The query is considered as a multiple Join problem (MJP). Reliable task-allocations for all permutations of MJP are found. The permutation which has minimum cost of data transmission is calculated. A method is suggested for calculating the reliability of the path that a DDBMS network follows to deliver a message to the receiver, given the number of spoolers.
The availability of a distributed database management system is defined as the fraction of transactions that are sucessfully executed out of all transactions that are submitted to the system over a given time interval...
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The availability of a distributed database management system is defined as the fraction of transactions that are sucessfully executed out of all transactions that are submitted to the system over a given time interval. Several variables that determine availability are addressed. These determinants are categorized as transaction traffic, reliability measures, data distribution, concurrency control, and fault tolerance. An evaluation expression for availability is presented in terms of these determinants. The method proposed in this paper is shown to provide several advantages compared to previous methods.
Recently, there has been a lot of work undertaken in the area of distributeddatabases. The architecture and syntax presented in this paper is a response to the very real need for the development of a unified approach...
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