• Title/Summary/Keyword: Shared Database

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Performance Analysis of Parallel Database Machine Architectures (병렬 데이타베이스 컴퓨터 구조의 성능 분석)

  • Lee, Yong-Kyu
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.4
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    • pp.873-882
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    • 1998
  • The parallel database machine approach is currently widely and successfully used. There are four major architectures which are used in this approach: shared-nothing architecture, shared-evertying architecture, shared-disk architecture, and hybrid architecture. In this paper, we use an analytical model to evaluate the performance of these database machine architectures. We define an abstract model for each type of database machine design to obtain performance equatons describing the execution times with respect to the hybrid hash join poeration. Using the performance equations, we evaluate the execution times of the various database machine design models.

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A Design of the Active Web Server Supporting Synchronous Collaboration in the Web-Based Group Collaboration Systems (웹 기반 그룹 협동 시스템에서 동기화된 협동을 지원하기 위한 능동형 웹 서버 설계)

  • 허순영;배경일
    • Proceedings of the Korea Database Society Conference
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    • 1999.06a
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    • pp.95-102
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    • 1999
  • The web-based group collaborative systems are emerging as enterprise-wide information systems. Since data in group collaborative systems are apt to be shared among multiple concurrent users and modified simutaneously by them, the web-based group collaborative systems must support synchronous collaboration in order to provide users with synchronized and consistent views of shared data. This Paper proposes an active web server which can facilitate synchronous collaboration in web-based group collaborative systems. To accomplish such a goal, the active web server manages dependency relationships between shared data and web browsers referencing them and actively propagates changing details of the shared data to all web browsers referencing them. And, this paper examines usefullness and effectiveness of the active web server to apply it to the ball-bearing design example of concurrent engineering design systems. The prototype system of the active web server is developed on a commercial Object-oriented Database Management System (ODBMS) called OBJECTSTORE using the C++ programming language.

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Development of an Object Consistency Maintenance Framework for Group Systems in Distributed Computing Environments (분산 환경에서 그룹시스템에서의 객체 일관성 유지를 위한 체계의 개발)

  • Huh, Soon-Young;Kim, Hyung-Min
    • Asia pacific journal of information systems
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    • v.8 no.3
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    • pp.21-36
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    • 1998
  • Group collaborative systems are recently emerging to support a group of users engaged in common tasks such as group decision making, engineering design, or collaborative writing. Simultaneously, as communications networks and distributed database systems become core underlying architecture of the organization, the need of collaborative systems are gaining more attentions from industry. In such collaborative systems, as the shared objects may evolve constantly or change for operational purposes, providing the users with synchronized and consistent views of the shared object and maintaining the consistency between shared object and replicated objects are important to improve the overall productivity. This paper provides an change management framework for the group collaborative systems to facilitate managing dependency relationships between shared objects and dependents, and coordinating change and propagation activities in distributed computing environments. Specifically, the framework adopts an object-oriented database paradigm and presents several object constructs capturing dependency management and change notification mechanisms. And the proposed framework accommodates both persistent dependents such as replicated data and transient dependents such as various user views in a single formalism. A prototype system is developed on a commercial object-oriented database management system called OBJECTSTORE using the C++ programming language.

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An Automated Search for Design Database by Shape Pattern Recognition (형상 패턴 인식을 이용한 설계자료의 자동 탐색)

  • 차주헌
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.04a
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    • pp.670-674
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    • 1996
  • In automated search of a design database to support mechanical design, it is necessaryto recognize a shape pattern which represents a design object. This paper introduces the concept of a surface relation graph (SRG) for recognizing shape patterns from a 3D boundary representation scheme of a solid model(a B-rep model). In SRG, the nodes and arcs correspond to the faces and edges shared by two adjacent faces, respectively. An attribute assigned to an arc is given by an integer which discriminates the relationship between two adjacent faces. The + sign of the integer represents the geometric convexity of the solid, and the -sign the concivity at the shared edge. The input shape is recognized by comparison with the predefined features which are subgraphs of the SRG. A hierarchyof the database for upporting the design is presented. A search for the design database is also discussed. The usefulness of this method is illustrated by some application results.

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Performance Evaluation of Disk Replacement Algorithms in a Shared Cluster (공유 디스크 클러스터에서 버퍼 고체 알고리즘의 성능 평가)

  • Cho, Haeng-Rae
    • Journal of KIISE:Databases
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    • v.35 no.6
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    • pp.469-480
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    • 2008
  • A shared disk (SD) cluster couples multiple nodes for high performance transaction processing, and all the coupled nodes share a common database at the disk level. To reduce the number of disk accesses, each node caches database pages in its memory buffer. Since a particular page may be cached simultaneously in different nodes, cache consistency should be maintained to ensure that nodes can always access the most recent version of database pages. Most cache consistency schemes proposed in the SD cluster adopted LRU as a buffer replacement algorithm. In this paper, we first present four buffer replacement algorithms that consider the characteristics of the SD cluster. Then we compare the performance of the buffer replacement algorithms. We perform the experiments on a variety of cluster configurations and database workloads. The experiment results show that the proposed algorithms achieve performance improvement up to 5 times of LRU algorithm.

Advanced Message Storing Method on mobilePOST SMSC (mobilePOST SMSC(Short Message Service Center)에서의 향상된 메시지 저장 기법)

  • Song, Byung-Kwen
    • Journal of the Korean Society for Railway
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    • v.11 no.2
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    • pp.126-138
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    • 2008
  • This paper proposes the preservation method that can effectively process short messages at mobilePOST SMSC(Short Message Service Center) platform on CDMA(Code Division Multiple Access). There are three techniques for the preservation method. First one is shared memory technique where several processes within the system share same memory to process transmission of short messages with maximum performance. Second one is to back-up messages in shared memory to the file system to prevent lost during system initialization or other unstable period. Third technique is that when transmission of short message was completed, finished message is moved from the shared memory to relational database for accounting purposes.

A Research of CALS Integrated Database Based on Federated Database Systems (연방 데이터베이스 시스템 기반의 CALS 통합 데이터베이스 구현 연구)

  • 우훈식;윤선희;정승욱;문희철
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.21 no.47
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    • pp.139-148
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    • 1998
  • CALS IDB (Integrated database) is one of core technologies that embodies the principle of a shared data environment for the life cycle related data in CALS environment. In this study, to successfully share the data, we first classified the data types employed in the CALS environment and then discussed the data heterogeneity issued in data integration processes. To effectively solve this heterogeneity, we proposed the federated database systems as a candidate system especially focusing on the major functions and core element technologies.

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Implementation of Web Service for the E_Commerce Database Processing (전자상거래의 DB처리를 위한 웹 서비스 구현)

  • 황하응;김정홍;이상조
    • Journal of the Korea Society of Computer and Information
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    • v.7 no.4
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    • pp.168-173
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    • 2002
  • According to the rapid growth of Internet service, electronic commerce usage scale is growing every year. It requires the method of vitalizations of electronic commerce through reducing the software development cost and making easy of data construction. Web service, which is adapting distributed technology based on internet supports the infrastructure of reducing the software development cost through software sharing. As the shared software modules access the same data, they can reference the same data on the other site. In this paper, we designed and implemented database Processing module of the electronic commerce program using web service technology, which can make easy of site construction and sharing database. Implemented database processing module supports data selection modification insertion deletion and searching. Using this functions we showed product item information could be shared among the other electronic commerce sit.

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Product Database Modeling for Collaborative Product Development

  • Do, Nam-Chul;Kim, Hyun;Kim, Hyoung-Sun;Lee, Jae-Yeol;Lee, Joo-Haeng
    • Proceedings of the CALSEC Conference
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    • 2001.08a
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    • pp.591-596
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    • 2001
  • To deliver new products to market in a due time, companies often develop their products with numerous partners distributed around the world. Internet technologies can provide a cheap and efficient basis of collaborative product development among distributed partners. This paper provides a framework and its product database model that can support consistent product data during collaborative product development. This framework consists of four components for representing consistent product structure: the product configuration, assembly structure, multiple representations and engineering changes. A product database model realizing the framework is designed and implemented as a system that supports collaborative works in the areas of product design and technical publication. The system enables participating designers and technical publishers to complete their tasks with shared and consistent product data. It also manages the propagation of engineering changes among different representations for individual participants. The Web technologies introduced in this system enable participants to easily access and operate shared product data in a standardized and distributed computing environment.

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Reliability Modeling of Shared Database System (공유 데이터베이스 시스템의 신뢰도 모델링)

  • Ro, Cheul-Woo;Kim, Ti-Na;Kang, Gi-Hyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.189-192
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    • 2005
  • In this paper, we present a Petri Net (PN) model for reliability analysis of a shared database system. The system consists of components; a database, two processors, two memory and a bus. The database should be operational and at least one of the component should be also operational. Otherwise system will be down. Each component can be failed and repaired individually. Stochastic Reward Net (SRN) Model for reliability analysis is developed. SRN is potential to define various reward function and can be easily used to obtain performance measures. The modeling techniques using variable cardinality, enabling function, timed transition priority in SRN are shown.

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