检索结果-内蒙古大学图书馆

International Conference on Utility and Cloud Computing

作者： Mukherjee, A. Watson, P. Newcastle Univ Sch Comp Sci Newcastle Upon Tyne NE1 7RU Tyne & Wear England

Grid computing enables users to perform computationally expensive applications on distributed resources acquired dynamically. Users are allowed to combine structured data and analysis components into new applications from distributed sites into new applications. distributed query processing offers an established way of structuring such computations, and well-known tools like OGSA-DAI and OGSA-DQP provide respectively a common interface to heterogeneous databases, and a way of exploiting distributed resources. Such significant benefits are however often undermined by high communication costs due to the need to move data between distributed resources. This paper describes an approach that addresses this by dynamically deploying query processing engines, analysis services and databases within virtual machines, on an internet-scale, so as to reduce communication costs. Results of internet-scale experiments are presented to demonstrate the performance benefits. Further, the use of dynamic deployment features based on requirements allows the creation of an ad-hoc runtime engine and thus opens up the possibility of creating a virtual marketplace for software and hardware resources. (C) 2011 Elsevier B.V. All rights reserved.

关键词： Grid computing Virtual organizations Web services distributed query processing Dynamic deployment Virtual machines

来源：评论

学校读者我要写书评

暂无评论

Executing In-network Queries Using SNEE

引用

28th British National Conference on Databases

作者： Galpin, Ixent Taylor, Robert Gray, Alasdair J. G. Brenninkmeijer, Christian Y. A. Fernandes, Alvaro A. A. Paton, Norman W. Univ Manchester Sch Comp Sci Manchester M13 9PL Lancs England

ISBN: (纸本)9783642245763;9783642245770

The SNEE query optimizer enables users to characterize data requests against wireless sensor networks (WSNs), using a declarative query language called SNEEql (SNEE for Sensor NEtwork Engine, described in [GBG+11], and publicly available at http://***/p/snee ). Queries are compiled into imperative query execution plans, which are translated into executable nesC source code. In this paper, we illustrate the lifecycle of a SNEEql query Q for in-network execution. This lifecycle encompasses the steps of preparatory metadata collection, followed by the compilation of Q into a query execution plan QEP, the dissemination of binary images implementing QEP throughout the WSN, and the generation of query results.

关键词： Wireless Sensor Networks In-network processing distributed query processing Stream query Languages

来源：评论

学校读者我要写书评

暂无评论

Learned distributed query Optimizer:Architecture and Challenges

引用

ZTE Communications 2024年第2期22卷 49-54页

作者： GAO Jun HAN Yinjun LIN Yang MIAO Hao XU Mo Peking University Beijing 100871China ZTE Corporation Shenzhen 518057China

The query processing in distributed database management systems(DBMS)faces more challenges,such as more operators,and more factors in cost models and meta-data,than that in a single-node DMBS,in which query optimization is already an NP-hard *** query optimizers(mainly in the single-node DBMS)receive attention due to its capability to capture data distributions and flexible ways to avoid hard-craft rules in refinement and adaptation to new *** this paper,we focus on extensions of learned query optimizers to distributed ***,we propose one possible but general architecture of the learned query optimizer in the distributed context and highlight differences from the learned optimizer in the single-node *** addition,we discuss the challenges and possible solutions.

关键词： distributed query processing query optimization learned query optimizer

来源：评论

学校读者我要写书评

暂无评论

Efficient time triggered query processing in wireless sensor networks

Efficient time triggered query processing in wireless sensor...

引用

4th International Conference on Embedded Software and Systems

作者： Scholz, Bernhard Gabor, Mohamed Medhat Dawborn, Tim Khoury, Raymes Tse, Edmund Univ Sydney Sydney NSW 2006 Australia CSIRO Hobart Tas Australia

ISBN: (纸本)9783540726845

In this paper we introduce a novel system that comprises techniques advancing the query processing in wireless sensor networks. Our system facilitates time triggered queries that are scheduled in a distributed fashion among sensor nodes. Thus, time synchronisation is of paramount importance. Since accurate time synchronisation requires more energy, our system allows a trade off between precision of time and energy according to the user requirements. To minimize the communication overhead for query processing, our system employs new query execution mechanisms. We have implemented our query processing system on Sun (TM) Small Programmable Object Technology (SPOT) sensor network platform. The system was entirely programmed in Java enabling an object oriented design and implement at ion. It provides a friendly graphical user interface for query managernent and visualisation of results.

关键词： wireless communications and ad hoc networks distributed query processing communication and energy optimisations time triggered protocols

来源：评论

学校读者我要写书评

暂无评论

Ranking distributed Probabilistic Data

Ranking Distributed Probabilistic Data

引用

35th ACM SIGMOD Conference

作者： Li, Feifei Yi, Ke Jestes, Jeffrey FSU Dept Comp Sci Tallahassee FL 32306 USA

ISBN: (纸本)9781605585543

Ranking queries are essential tools to process large amounts of probabilistic data that encode exponentially many possible deterministic instances. In many applications where uncertainty and fuzzy information arise, data are collected from multiple sources in distributed, networked locations, e.g., distributed sensor fields with imprecise measurements, multiple scientific institutes with inconsistency in their scientific data. Due to the network delay and the economic cost associated with communicating large amounts of data over a network, a fundamental problem in these scenarios is to retrieve the global top-k tuples from all distributed sites with minimum communication cost. Using the well-founded notion of the expected rank of each tuple across all possible worlds as the basis of ranking, this work designs both communication- and computation-efficient algorithms for retrieving the top-k tuples with the smallest ranks from distributed sites. Extensive experiments using both synthetic and real data sets confirm the efficiency and superiority of our algorithms over the straightforward approach of forwarding all data to the server.

关键词： distributed query processing probabilistic data ranking queries top-k uncertain databases

来源：评论

学校读者我要写书评

暂无评论

DeXIN: An Extensible Framework for distributed Xquery over Heterogeneous Data Sources

DeXIN: An Extensible Framework for Distributed XQuery over H...

引用

11th International Conference on Enterprise Information Systems

作者： Ali, Muhammad Intizar Pichler, Reinhard Truong, Hong-Linh Dustdar, Schahram Vienna Univ Technol Database & Artificial Intelligence Grp Vienna Austria Vienna Univ Technol Distributed Syst Grp Vienna Austria

ISBN: (纸本)9783642013461

In the Web environment, rich, diverse sources of heterogeneous and distributed data are ubiquitous. In fact, even the information characterizing a single entity - like, for example, the information related to a Web service - is normally scattered over various data sources using various languages such as XML, RDF, and OWL. Hence, there is a strong need for Web applications to handle queries over heterogeneous, autonomous, and distributed data sources. However, existing techniques do not provide sufficient support for this task. In this paper we present DeXIN, an extensible framework for providing integrated access over heterogeneous, autonomous, and distributed web data sources, which can be utilized for data integration in modern Web applications and Service Oriented Architecture. DeXIN extends the Xquery language by supporting SPARQL queries inside Xquery, thus facilitating the query of data modeled in XML, RDF, and OWL. DeXIN facilitates data integration in a distributed Web and Service Oriented environment by avoiding the transfer of large amounts of data to a central server for centralized data integration and exonerates the transformation of huge amount of data into a common format for integrated access.

关键词： Data integration distributed query processing Web data sources Heterogeneous data sources

来源：评论

学校读者我要写书评

暂无评论

Mutant query plans

Mutant query plans

引用

16th Annual ACM Conference on Object-Oriented Programming Systems, Languages, and Applications (OOPSLA)

作者： Papadimos, V Maier, D Oregon Hlth Sci Univ OGI Sch Sci & Engn Dept Comp Sci & Engn Beaverton OR 97006 USA

We propose a flexible and robust framework for distributed query processing based on mutant query, plans (MQP). A MQP is an XML representation of a query plan that can also include verbatim XML data, references to resource locations (URLs), or abstract resource names (URNs). Servers work using local, possibly incomplete knowledge, partially evaluate as much of the query plan as they can, incorporate the partial results into a new, mutated query plan and transfer it to some other server that can continue processing. We have implemented an initial version of this framework, and present preliminary performance results. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词： distributed query processing partial evaluation XML

来源：评论

学校读者我要写书评

暂无评论

Effcient distributed Skyline Queries for Mobile Applications

引用

Journal of Computer Science & Technology 2010年第3期25卷 523-536页

作者：肖迎元陈跃国 Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology Tianjin University of Technology Key Laboratory of Computer Vision and System Tianjin University of Technology School of Computing National University of Singapore Key Laboratory of Data Engineering and Knowledge Engineering Renmin University of China

In this paper, we consider skyline queries in a mobile and distributed environment, where data objects are distributed in some sites （database servers） which are interconnected through a high-speed wired network, and queries are issued by mobile units （laptop, cell phone, etc.） which access the data objects of database servers by wireless channels. The inherent properties of mobile computing environment such as mobility, limited wireless bandwidth, frequent disconnection, make skyline queries more complicated. We show how to efficiently perform distributed skyline queries in a mobile environment and propose a skyline query processing approach, called efficient distributed skyline based on mobile computing （EDS-MC）. In EDS-MC, a distributed skyline query is decomposed into five processing phases and each phase is elaborately designed in order to reduce the network communication, network delay and query response time. We conduct extensive experiments in a simulated mobile database system, and the experimental results demonstrate the superiority of EDS-MC over other skyline query processing techniques on mobile computing.

关键词： skyline distributed query processing mobile database system

来源：评论

学校读者我要写书评

暂无评论

Variation of Bloom Filters Applied in distributed query Optimization

Variation of Bloom Filters Applied in Distributed Query Opti...

引用

作者： Yue (Amber) Zhang University of Windsor

学位级别：硕士

distributed query processing is important for distributed Database Systems. Through the past years, the research focus in distributed query processing has been on how to realize join operations with different operators such as serni-join and Bloom Filter. Experiments show that using bloom ﬁlters, the hash-sernijoin, almost always does better than semi- join for the query processing. However as long as you use bloom ﬁlter, you carmot avoid collisions. So in order to get the cheaper processing, some of the past work uses two or more bloom ﬁlters to do the hash-semijoin. However several factors still affect the cost and optimization result. 1. How to decide the perfect number of the bloom ﬁlters, and what kind of bloom ﬁlter should be chosen. 2. There is no way to avoid collisions when utilizing bloom ﬁlters. 3. With bloom ﬁlter, we cannot keep the exact location information of the joining attributes (loss of join information). 4. With bloom ﬁlter, we never can combine the useful composite semi-join in the process. Taking the idea of PERF join into account, why not use the bloom ﬁlter (hash-semijoin) concept but come up with a new kind of ﬁlter "Complete Reducing Filter" (CRF), which can avoid the disadvantages of bloom ﬁlter, as well as inherit the advantages of it? We propose and implement a new algorithm called Complete Reducing Filter (CRF) based on PERF join, which can keep the join location information, as well as lower transmission cost (because it's still using the ﬁlter concept). At the same time, CRF can combine the composite semi-join into the process, which overcome the impossibility if only using a bloom ﬁlter. With the variation of the bloom ﬁlter, we try to achieve better performance with lower cost.

关键词： distributed query processing semi-join bloom filter hash-semijoin composite semi-join

来源：评论

学校读者我要写书评

暂无评论

STOCHASTIC query OPTIMIZATION IN distributed DATABASES

引用

ACM TRANSACTIONS ON DATABASE SYSTEMS 1993年第2期18卷 262-288页

作者： DRENICK, PE SMITH, EJ POLYTECH INST NEW YORK DEPT ELECT ENGN COMP SCIBROOKLYNNY 11201

Many algorithms have been devised for minimizing the costs associated with obtaining the answer to a single, isolated query in a distributed database system. However, if more than one query may be processed by the system at the same time and if the arrival times of the queries are unknown, the determination of optimal query-processing strategies becomes a stochastic optimization problem. In order to cope with such problems, a theoretical state-transition model is presented that treats the system as one operating under a stochastic load. query-processing strategies may then be distributed over the processors of a network as probability distributions, in a manner which accommodates many queries over time. It is then shown that the model leads to the determination of optimal query-processing strategies as the solution of mathematical programming problems, and analytical results for several examples are presented. Furthermore, a divide-and-conquer approach is introduced for decomposing stochastic query optimization problems into distinct subproblems for processing queries sequentially and in parallel.

关键词： ALGORITHMS PERFORMANCE THEORY distributed query processing STATE-TRANSITION MODEL STOCHASTIC query OPTIMIZATION

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：