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EVALUATING MULTIPLE JOIN QUERIES IN A distributed database system

MATHEMATICAL AND COMPUTER MODELLING 1995年第7期21卷 83-98页

作者： REID, DJ Distributed Systems Technology Centre Department of Computer Science The University of Queensland St. Lucia Queensland 4072 Australia

It is proposed that the execution of a set of join queries in a distributed environment should be considered cooperatively, rather than as a set of separate requests. With this understanding, a model of multiple query execution in the form of a linear integer program is offered. Several requests are issued to the distributed database management system, each specifying the collation of information comprised of a number of logically distinct data sets, or relations, and dispersed across the sites of a distributed system. Performing these tasks demands the usage of limited resources, so that efficient management commands the smallest additional imposition possible. Both processors and the data communication devices that interconnect them are exploited;an optimal strategy is defined to be one that minimizes a weighted sum of the costs of computation and those of information exchange incurred in resolving the group of queries. Previous models of join query evaluation would regard each individual query in isolation, to produce a sequence of independent execution strategies, one correspondingly for every request. By instead permitting multiple utilization of intermediate computations, any overlap between these queries can be exploited to further reduce the total demand placed on the system as a whole. Through investigations into the character of a number of interacting join computations, performed at a single site in isolation, an earlier single query model [1] can be extended to facilitate the cooperative execution of an entire group.

关键词： distributed database system INTEGER PROGRAM JOIN QUERY RELATIONAL database

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Vertical partitioning method for secret sharing distributed database system

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IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2006年第11期E89A卷 3244-3249页

作者： Miyamoto, Toshiyuki Morita, Yasuhiro Kumagai, Sadatoshi Osaka Univ Grad Sch Engn Suita Osaka 5650871 Japan

Secret sharing is a method for distributing a secret among a party of participants. Each of them is allocated a share of the secret, and the secret can only be reconstructed when the shares are combined together. We have been proposing a secret sharing distributed database system (SSDDB) that uses a secret sharing scheme to improve confidentiality and robustness of distributed database systems. This paper proposes a vertical partitioning algorithm for the SSDDB, and evaluates the algorithm by computational experiments.

关键词： distributed database system multi-agent systems secret sharing scheme vertical partitioning

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A coordinated planning model for the design of a distributed database system

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INFORMATION SCIENCES 2004年第1-4期164卷 229-245页

作者： Amiri, A Oklahoma State Univ Dept MSIS Coll Business 210 Stillwater OK 74078 USA

Motivated by a problem faced by a multimedia entertainment retailer, we explore the problem of planning the design of a distributed database system. The problem consists of planning the design/expansion of the distributed database system by introducing new database servers and retiring possibly some existing ones in order to reduce telecommunication costs for processing user queries and server acquisition, operations and maintenance cost in a multiperiod environment where user processing demand varies over time. We develop a mathematical programming model and an effective solution approach to determine the best decisions regarding acquisition and retirement of database servers and assignment of user processing demand to the servers over time. Through a computational study, we investigate the impact of important parameters such as length of the planning horizon and demand growth on the solution quality and utilization of server capacity and examine the effectiveness of the solution approach in comparison with the commercial package LINDO. We also discuss some extensions to the problem as directions for future research. (C) 2003 Elsevier Inc. All rights reserved.

关键词： planning distributed database system database servers mathematical programming heuristic

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ALLOCATING RELATIONS IN A distributed database system

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MATHEMATICAL AND COMPUTER MODELLING 1995年第8期22卷 33-47页

作者： REID, DJ ORLOWSKA, M Department of Computer Science The University of Queensland St. Lucia Queensland 4072 Australia

A model is proposed that allocates tables of a relational database to the sites of a distributed system in order that the total cost of executing a given collection of join queries is minimized. This model is presented in the convenient form of an integer linear program. Each individual query specifies that several logically distinct data sets, or relations, are to be amalgamated and presented to the particular user that issued the request. Performing this task requires the utilization of limited system resources;both processors, and the communications facilities that interconnect them, may be used. An optimal strategy for executing a single query is, therefore, defined to be one that minimizes a weighted sum of the costs of computation, and those of information interchange, incurred during the computation. One particular model, appearing in [1], conforms to this philosophy, and so forms the basis for further investigations. The total cost of executing an entire group of such queries depends upon the way in which the relevant information is allocated to the sites of the network. Several copies of any particular relation may be dispersed across the network;the replication of data increases its availability, and potentially decreases the costs of answering the given requests. However, only limited storage capacities are available, and increased replication commands greater overheads in maintaining consistency. An optimization program is developed to design a data allocation plan that achieves a minimal total cost for the execution of a given group of requests, while maintaining restraints on the levels of data replication considered permissible.

关键词： distributed database system INTEGER PROGRAM JOIN QUERY RELATIONAL database

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Minimizing the response time of executing a join between fragmented relations in a distributed database system

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MATHEMATICAL AND COMPUTER MODELLING 1997年第1期25卷 59-75页

作者： Reid, DJ Information Technology Division Defence Science and Technology Organisation P.O. Box 1500 Salisbury SA 5108 Australia

The problem of describing minimal response time execution strategies in evaluating the join of several fragmented database relations, is considered. The consequential optimization problem assumes the convenient form of a min-max integer program. With further attention, various generalizations are realized that also include the performance objective of total execution cost. Tables of data logically conforming to the relational model of information are, at the physical level, frequently divided into numerous pieces. These fragments are found disseminated amongst the various sites of a distributed database system, with each one possibly replicated at any number of separate facilities. A submission demanding the amalgamation of many such relations is resolved by joining together their sets of component fragments in an appropriate manner, as defined by complicated patterns of overlapping attribute values. The final result is realized by then concatenating the products of these computations. This process is to be performed under the supervision of the database management system in such a way as to minimize the time taken, as perceived by the user who issued the request. These developments are based upon earlier investigations [1-5] that consider only the alternative optimization goal of minimal execution cost. With this in mind, several different different approaches may be taken to realize distinct hybrid models that give due regard to both measures of join query performance.

关键词： distributed database system integer program join query relational database

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RESILIENT EXTENDED TRUE-COPY TOKEN SCHEME FOR A distributed database system

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IEEE TRANSACTIONS ON SOFTWARE ENGINEERING 1982年第3期8卷 173-189页

作者： MINOURA, T WIEDERHOLD, G STANFORD UNIV DEPT COMP SCISTANFORDCA 94305

The problem of failure recovery for a distributed database system is more complex than that for a centrally controlled database system. If all the sites in a distributed system whose data are updated by a transaction are not up and available at the time of transaction execution, either the updates must be cancelled for all sites or the updates for the temporarily inaccessible site must be saved for later delivery. A resilient control scheme for a distributed database system is described. The notion of a resilient system holds that a transaction cannot be executed if some true copies required by the transaction are not available within the partition where the transaction is executing. system objectives include the elimination of lost transaction updates, where the user receives an acknowledgment but updates are not posted, and lost transaction output, where updates are posted but the user receives no acknowledgment. Figures.

关键词： True Copy Token distributed database system Logical Data Replicated Data Resiliency Control

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A web-based design for the mobile transaction management of a distributed database system 27

A web-based design for the mobile transaction management of ...

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Technology of Object-Oriented Languages International Conference (TOOLS 27)

作者： Zhong, JT Zhou, WL Deakin Univ Sch Comp & Math Geelong Vic 3217 Australia

ISBN: (纸本)0818690968

A mobile transaction management system enables users to receive transaction based services from both static and mobile hosts distributed in a large scale of network. The difficulty lies in the heterogeneity of computer systems and in the communication control to guarantee concurrency and consistency of transaction operations. The World Wide Web offers a uniformed vehicle to interface with users ubiquitously and an ideal architecture to implement mobile transaction systems. This paper reports a design using Java, JDBC and Web browser to implement a distributed database system, particularly a transaction management system covers mobile hosts and static workstations/PCs in which data and sewers are replicated.

关键词： transaction management World Wide Web distributed database system

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Interference-Free Checkpointing Algorithm for distributed database system

Interference-Free Checkpointing Algorithm for Distributed Da...

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International Conference on Industrial Control and Electronics Engineering (ICICEE)

作者： Luo, Chaojin Motorola China Chengdu R&D Ctr Chengdu Peoples R China

ISBN: (纸本)9780769547923

Checkpointing Algorithm is widely used in distributed database system (DDBS) to recover DDBS from fault. In traditional algorithms, normal DDBS activities, i.e. message exchanging between distributed sites should be blocked in checkpointing, thus the DDBS service are interfered with and the DDBS availability is dropped down. This paper presents a new algorithm that does not impact DDBS normal processing in checkpointing, and hence promote the DDBS availability.

关键词： Interference-Free Consistent Global Checkpoint Recovery Point distributed database system

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A New distributed Mining Association Rules Algorithm in distributed database system

A New Distributed Mining Association Rules Algorithm in Dist...

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International Conference on Smart Materials and Intelligent systems

作者： Gao, Shutao School of Service Outsourcing Hunan Foreign Economic Relations and Trade College China

ISBN: (纸本)9780878492237

The traditional algorithms create the local candidate sets firstly, and then determine whether the local frequent item sets is the global frequent item sets by the traffic between the nodes. The most different between the proposed algorithm and the traditional algorithms is that it firstly generates all the local frequent item sets at each node and then communicates to the top point. At the top point, there are four cases to deal with all the local frequent item sets. For the fastest case, the determination could be made by the completion of round-trip communications. At the same time, all the operations of this algorithm are completed not by traditional data storage but by a new data storage in which the item is considered as the keyword. The method can save storage space, especially for sparse data. So the support can be calculated by the intersection of the transaction sets, which is much easier than by accessing to the database. Finally, the association rules in the distributed database are mined.

关键词： mining association rules distributed database system algorithm

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A 3-tiered client-server distributed database system component-based 04

A 3-tiered client-server distributed database system compone...

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Proceedings of the winter international synposium on Information and communication technologies

作者： Francisco Álvarez Cavazos Juan Carlos Lavariega Jarquín Instituto Tecnológico y de Estudios Superiores de Monterrey Monterrey México

The administration of distributed data is a need that nowadays many enterprises strive to fulfill. However, it is often difficult for these enterprises to find a software product capable of providing the solution they require. This is due to the inherent complexity to distributed data access, which has caused the majority of database applications to provide distributed access to a centralized database as a simpler alternative to distributed database systems. This article demonstrates that it is possible to design a component-based reference architecture of a distributed database systems (D-DBS) with a 3-tiered client-server structure from the solution given to the data distribution problem through the implementation of a global conceptual schema. Therefore, this proposal reduces the design complexity of a D-DBS.

关键词： 3-tiered client-server system component software architecture component-based system data distribution data integration middleware distributed database system

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