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21st Iranian Conference on Electrical Engineering (ICEE)

作者： Firoozandeh, Sadegh Staff Pooya Co Inc Tehran Iran

ISBN: (纸本)9781467356343

This paper applies the traditional read-only optimization in the one and two phase protocols of commit processing in the context of pure main memory database systems. Thereby there is no need for logging log records to backup node in read-only transactions. Through this optimization, the response time will be decreased in these transactions. Furthermore, the message complexity will be decreased which leads to the decrease of communicative traffic overhead during commit processing in distributed systems. This decrease in multi-level distributed transactions which are the most common types of transactions is more observable. Also, a new read-only optimization is proposed about two phase protocols that remove both the commit processing phases for read-only transactions and also removes all the logging activities to backup node for partially read-only transactions. As a result, response times, the message and log complexity, and transactions concurrency level in comparison to traditional read-only optimization will be improved more.

关键词： distributed database system Main memory database Transaction processing Commit processing Primary-backup system

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Security and Privacy Challenges in distributed database Management systems

Security and Privacy Challenges in Distributed Database Mana...

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2023 IEEE Global Conference on Information Technologies and Communications, GCITC 2023

作者： Kumar, Santosh Dash, Kishor Kumar Piduru, Bhargav Reddy Rajkumar, K. Bhaskar, Bandi Tiwari, Mohit Era University Department of Computer Science Uttar Pradesh Lucknow India Balimela College of Science and Technology Berhampur University and Govt. Model Degree College Study Centre Odisha State Open University Faculty & Academic Counsellor Department of Botany and Journalism & Mass Communication India Customer Experience Architect Hyundai IrvineCA United States /CSE Department Tamilnadu Kovilpatti India Sr University School of Cs & Ai Telangana Warangal India Bharati Vidyapeeth's College of Engineering Department of Computer Science and Engineering Delhi India

ISBN: (纸本)9798350308167

This research aims to investigate the challenge of recognizing and evaluating distributed database management system (DDBMS) security and privacy challenges and also to describe important danger indicators that may lead to possible data security difficulties in distributing resources, both tangible and functioning. An investigation of the primary DDBMS security and privacy challenges that can be found while developing and managing a standard DDBMS meant for supporting data procedures and offering data services was conducted as a component of this research. The data assessment was produced depending on the findings of surveys and questionnaires administered to DDBS security and privacy professionals with varying degrees of training and emphases in their operations within this expertise field. The findings of the research include a list of primary risk variables based on their significance and frequency in practice, and also a spotlight on the most important security and privacy measures. This article summarizes data on traditional methods to illustrate data security challenges employing statistical, qualitative, and mixed evaluation, and also the most recent techniques depending on smart categorization and examination of DDBS security and privacy challenge factors and functioning with huge amounts of data. © 2023 IEEE.

关键词： and distributed database management system Challenges distributed database system Privacy Security

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Distribuovaný dokumentový server založený na databázi CouchDB

Distribuovaný dokumentový server založený na databázi C...

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作者： Kanis, Martin Brno University of Technology

Práca pojednáva o problematike distribuovaných databázových systémov, o ich výhodách a nevýhodách. Následne text oboznamuje s dokumentovou databázou CouchDB,... 详细信息

Práca pojednáva o problematike distribuovaných databázových systémov, o ich výhodách a nevýhodách. Následne text oboznamuje s dokumentovou databázou CouchDB, spôsobom ukladania dokumentov, riešením synchronizácie a prístupu ku CAP teorému. Cieľom práce je implementovať distribuovaný databázový server pre správu a workflow dokumentov, ktorý je založený na CouchDB. Systém obsahuje cluster s troma CouchDB uzlami a HAProxy na popredí, ktorá rozdeľuje záťaž medzi uzlami. Systém umožňuje vytváranie ľubovoľných dokumentov na základe šablóny, spravuje ich životný cyklus a tok. Taktiež je možné vytvárať vlastné workflow za pomoci BRMS pravidiel. Implementované riešenie uľahčuje spravovanie a tok dokumentov a umožňuje vysokú mieru prispôsobenia potrebám organizácie.

关键词： Distribuované databázové systémy CouchDB Synchronizácia CAP teorém B-stromy Správa dokumentov Tok dokumentov distributed database system CouchDB Synchronization CAP theorem B-trees Document management Workflow Text

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A LIUB(LOG(2)(N))-2 RESILIENT DECENTRALIZED COMMIT PROTOCOL

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IEEE TRANSACTIONS ON RELIABILITY 1994年第4期43卷 594-599页

作者： YUAN, SM National Chiao Tung University Hsinchu Taiwan

In distributed database systems, commit protocols are used to ensure the transaction atomicity. In the presence of failures, nonblocking commit protocols can guarantee the transaction atomicity without blocking the transaction execution. A (resilient) decentralized nonblocking commit protocol (RDCP) is proper-ed for distributed database systems. This protocol is based on the hypercube network topology and is 'liub(log(2)(N)) - 2' resilient to node failures (N = number of system-nodes). The number of messages sent among the N nodes is 0(***(2)(2)(N)) which is only a factor of log(2)(N) over the message complexity lower bound 0(***(2)(N)) of decentralized commit protocols. Furthermore, RDCP is an optimistic nonblocking protocol. It aborts the transaction only when some nodes want to abort or some nodes fail before they make local decisions.

关键词： distributed database system COMMIT PROTOCOL DECENTRALIZED ALGORITHM RESILIENCE HYPERCUBE MESSAGE COMPLEXITY

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Reliability-based mirroring of servers in distributed networks

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IEICE TRANSACTIONS ON COMMUNICATIONS 2002年第2期E85B卷 540-549页

作者： Nakaniwa, A Takahashi, J Ebara, H Okada, H Kansai Univ Fac Engn Suita Osaka 5648680 Japan

In this paper, we consider optimal mirror allocation problems for the purpose of load balancing in network servers. We focus on constructing high-reliability networks and propose the optimal mirror allocation model such that the system reliability is maximized subject to costs and delays, in view of the trade-off between the reliability and cost. This optimization model is capable of dealing with various kinds of network topologies, although for simplicity, we assume the read-only situation. We formulate this optimization problem into a 0 1 integer programming model, and we use an approximate method for numerical analysis in order to analyze more large-scale systems. Our objective is to find the optimal mirror allocation by solving this model, and to show quantitatively the general characteristics of the load balancing and the improvement of the system reliability by the distributed mirror allocation.

关键词： load balancing reliability mirroring distributed database system Internet

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A Comprehensive Taxonomy of Fragmentation and Allocation Techniques in distributed database Design

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ACM COMPUTING SURVEYS 2018年第1期51卷 12-12页

作者： Nashat, Dalia Amer, Ali A. Assiut Univ Fac Sci Dept Math Assiut Egypt Taiz Univ Fac Sci Dept Math Taizi Yemen

The need to design an optimally distributed database is increasingly important with the growth of information technology and computer networks. However, designing a distributed database is an extremely complex process due to a large number of geographically distributed sites and database relations. Moreover, decreasing communication costs and query response time should be taken into consideration. There are three main techniques applied to design a distributed database, namely Fragmentation, Data allocation, and Replication. It is notable that these techniques are often treated separately and rarely processed together. Some available allocation methods are applied regardless of how the fragmentation technique is performed or replication process is adopted. In contrast, other fragmentation techniques do not consider the allocation or the replication techniques. Therefore, the first and foremost step for designing an optimal database is to develop a comprehensive understanding of the current fragmentation, replication, and allocation techniques and their disadvantages. This article presents an attempt to fulfill this step by proposing a comprehensive taxonomy of the available fragmentation and allocation techniques in distributed database design. The article also discusses some case studies of these techniques for a deeper understanding of its achievements and limitations.

关键词： Allocation distributed database system horizontal fragmentation hybrid fragmentation replication vertical fragmentation

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Smartlog - A declarative language for distributed programming in smart grids

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COMPUTERS & ELECTRICAL ENGINEERING 2019年 80卷 106499-000页

作者： Thi-Thanh-Quynh Nguyen Debusschere, Vincent Bobineau, Christophe Quang Huy Giap Hadjsaid, Nouredine Univ Grenoble Alpes CNRS Grenoble INP Inst EngnG2Elab F-38000 Grenoble France Univ Grenoble Alpes CNRS Grenoble INP Inst EngnLIG F-38000 Grenoble France Univ Danang Univ Sci & Technol Dept Elect Engn Da Nang Vietnam

In the control and supervision of smart grids, the objective is to handle any change in the system as fast as possible, with as few resources as possible. In this context, this paper proposes a new language, called Smartlog, designed with a declarative approach. This avoids collecting and analyzing data presenting no interest, and thus being less efficient in bandwidth usage and computational time. Smartlog is designed for operating smart grids defined as abstract structures of large and scalable distributed databases. From its definition, some major properties of this language, such as simplicity, incremental capacity, and scalability are highlighted. The language is tested on the application of the secondary control of an isolated microgrid using a real-time simulator connected to Raspberry Pis. The characteristics of Smartlog are illustrated thanks to a comparison with an imperative programming implementation of the same regulation. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Smartlog Smart grids Declarative programming distributed database system Secondary control Discrete-time control

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分散式資料庫檔案配置之最佳化模式

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Journal of Industrial and Production Engineering 2000年第6期17卷 643-650页

作者： H. L. Li[a] H. C. Shu[a] T. S. Lee[a] [a]Institute of Information Managemet National Chiao Tung University

摘要摘要隨著網際網路的普及，資料可於組織內透過網路連結，將分散於各地的資料庫伺服器連結；亦即可在組織內架設一分散式資料庫，提供使用者多元化的查詢服務。而其最關鍵問題即爲如何在數個資料庫中決定檔案的儲存位置，使使用者的... 详细信息

摘要摘要隨著網際網路的普及，資料可於組織內透過網路連結，將分散於各地的資料庫伺服器連結；亦即可在組織內架設一分散式資料庫，提供使用者多元化的查詢服務。而其最關鍵問題即爲如何在數個資料庫中決定檔案的儲存位置，使使用者的總査詢時間爲最短。本研究提出一資料檔配置模式，在有限的空間資源及允許資料檔多重備份的情況下，決定網路中最佳的資料檔配置策略。此模式的計算效率比現有方法[2][4][5]高出許多。AbstractWith popularity of Internet, data can be linked with distributed databases by building a distributed database. One of most critical problems in distributed database design is to decide the locations of several DBs thus to minimize the total time of users’ *** study proposes a data file allocation model under limited resources. The proposed model has better computational efficiency comparing with current models [2][4][5].

关键词：分散式資料庫資料檔配置 distributed database system data allocation

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A Comparison of Two database Partitioning Approaches that Support Taxonomy-Based Query Answering 20

A Comparison of Two Database Partitioning Approaches that Su...

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Proceedings of the 22nd International Conference on Information Integration and Web-based Applications & Services

作者： Jero Mario Schäfer Lena Wiese Institute of Computer Science University of Göttingen Göttingen Germany Institute of Computer Science Goethe University Frankfurt Frankfurt Germany

ISBN: (纸本)9781450389228

In this paper we address the topic of identification of cohorts of similar patients in a database of electronic health records. We follow the conjecture that retrieval of similar patients can be supported by an underlying distributed database design. Hence we propose a fragmentation based on partitioning the health records and present a benchmark of two implementation variants in comparison to an off-the-shelf data distribution approach provided by Apache Ignite. While our main use case in this paper is cohort identification, our approach has advantages for taxonomy-based query answering in other (non-medical) domains.

关键词： relational databases taxonomy-based query answering distributed database system

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Design and Implementation of DB-MANα: Does database Migration Work Well in a Real Environment? 02

Design and Implementation of DB-MANα: Does Database Migrati...

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Australasian database Conference

作者： Toyokazu Akiyama Shinobu Sakai Akimichi Umigai Takahiro Hara Masahiko Tsukamoto Shojiro Nishio Applied Information Systems Division Cybermedia Center Osaka University 5-1 Mihogaoka Ibaraki Osaka 567-0047 Japan

ISBN: (纸本)0909925836

Due to the recent expansion of network bandwidth, the data propagation delay has become a significant factor which influences the system performance in place of the data transmission delay. Based on this fact, we have proposed a new technology to reduce the bad influence of propagation delay on the performance of distributed database system by relocating dynamically the database through networks, which we call database migration. Furthermore, we have proposed a database relocation method to choose the transaction processing method between the conventional database fixed method and the proposed database migration method by giving consideration to the transaction complexity. In this paper, we explain our distributed database system with database migration mechanism based on these proposals, and the implementation of the DB-MANα system as a prototype system. The DB-MANα system reduces the database migration time by using a main memory database technique, which induces us to add a backup management mechanism for migratory databases. Moreover, we show some measurement results for the performance evaluation of the DB-MANα system. The results show that the implemented system works well in a practical environment.

关键词： database migration distributed database system transaction processing database migration distributed database systems Propagation delay WELLS

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