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Dynamic Multiroot, Multiquery processing Based on Data Sharing In Sensor Networks

ACM TRANSACTIONS ON SENSOR NETWORKS 2010年第3期6卷 25.1-25.38页

作者： Zhang, Zhiguo Kshemkalyani, Ajay D. Shatz, Sol M. Univ Illinois Dept Comp Sci Chicago IL 60607 USA

Applications that exploit the capabilities of sensor networks have triggered significant research on query processing in sensor systems. Energy constraints make optimizing query processing particularly important. This article addresses multiroot, multiquery optimization for region queries. The work focuses on application-layer issues exploiting query semantics. The article formulates three algorithms: a naive algorithm, without data sharing, and a static and heuristic data-sharing algorithm. The heuristic algorithm allows sharing of partially aggregated results of preconfigured geographic regions and exploits the location attribute of sensor nodes as a grouping criterion. Simulation studies indicate the potential for significant energy savings with the proposed algorithms.

关键词： Algorithms Design Performance Sensor networks distributed query processing geographic coverage multiquery optimization

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ADAPTIVE SELECTION OF MATERIALIZED QUERIES IN A MEDIATOR

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PARALLEL processing LETTERS 2005年第4期15卷 451-458页

作者： Joo, Kil Hong Lee, Won Suk Yonsei Univ Dept Comp Sci 134 Sedaemoongu Shinchondong Seoul South Korea

In a mediator, query usage should be carefully monitored to determine the optimized set of materialized sub-queries, since the integration schema of a mediator can be incrementally modified and the evaluation frequency of a global query can also be continuously varied. This paper proposes a theoretical basis for adaptive selection of materialized sub-queries such that available storage in a mediator can be highly utilized at any time. In order to differentiate the recent usage of a query from the past, the accumulated usage frequency of a query decays as time goes by. Consequently, it is possible to find the optimum set of materialized sub-queries which minimizes the total evaluation cost of global queries in linear search complexity.

关键词： Mediator heterogeneous information systems data materialization distributed query processing decay rate

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Execution of distributed queries in the web environment

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JOURNAL OF COMPUTATIONAL METHODS IN SCIENCES AND ENGINEERING 2006年第5-6期6卷 S243-S254页

作者： Hu, Gongzhu Zhang, David Cent Michigan Univ Dept Comp Sci Mt Pleasant MI 48859 USA Cent Michigan Univ Coll Extended Learning Mt Pleasant MI 48859 USA

Database query processing is one of the fundamental issues in data engineering, particularly when more and more databases become distributed over the Internet in the last decade. There have been several approaches to the problem of distributed query processing (DQP), some were successful in the client-server environment but not so in an environment with heterogeneous and autonomous databases. The challenge relies on the nature of the Internet and the Web that pose many difficulties to the problem in hand. In this paper, we propose a model that uses an XML standard and its equivalent inmemory data structure to achieve data sharing, and invokes XML Web services in asynchronous mode to allow local database management systems to efficiently process local data. This approach, like XJoin, allows progress to be made even when data sources experience delays. It builds a layer on top of existing database management systems to minimize the complexity and cost for processing distributed queries that is critical for making such a method practical.

关键词： distributed query processing data sharing query decomposition XJoin

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Performance and scalability of XML query processing

Performance and scalability of XML query processing

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International Conference on Complex, Intelligent and Software Intensive Systems

作者： Gaetan HAINS Muath ALRAMMAL Laboratoire d'Algorithmique Complexite et Logique Universite Paris-Est

ISBN: (纸本)9781467312332

This paper discusses basic issues about the performance of semi-structured query processing in very large datasets. It is based on recent algorithm-engineering work, on the state of the art in performance management for XML query processing and on theoretical studies about the complexity structure of the querying problem. Its main conclusions provide a concrete view on the interaction between terabyte scale XML data, query complexity and current or future computer architectures. To provide a concrete and synthetic view of this diverse body of knowledge, the presentation follows a fictional use case whose characters face query problems of varying complexity that are set in multiple contexts and analyzed today before being projected to 2020 and 2030.

关键词： Parallel and stream-processing for XML queries Scalability of queries and XPath fragments Optimization of data mining applications that use XML databases query analysis extensible markup language Scalability Computer Architecture distributed query processing relational query processing Performance management Concrete Theoretical Study

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querying Complex Spatio-Temporal Sequences in Human Motion Databases

Querying Complex Spatio-Temporal Sequences in Human Motion D...

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IEEE 24th International Conference on Data Engineering (ICDE 2008), vol.1

作者： Yueguo Chen Shouxu Jiang Beng Chin Ooi Anthony K. H. Tung School of Computing National University of Singapore Singapore School of Computer Science and Technology Harbin Institute of Technology Harbin China

ISBN: (纸本)9781424418367;1424418364

Content-based retrieval of spatio-temporal patterns from human motion databases is inherently nontrivial since finding effective distance measures for such data is difficult. These data are typically modelled as time series of high dimensional vectors which incur expensive storage and retrieval cost as a result of the high dimensionality. In this paper, we abstract such complex spatio-temporal data as a set of frames which are then represented as high dimensional categorical feature vectors. New distance measures and queries for high dimensional categorical time series are then proposed and efficient query processing techniques for answering these queries are developed. We conducted experiments using our proposed distance measures and queries on human motion capture databases. The results indicate that significant improvement on the efficiency of query processing of categorical time series (more than 10,000 times faster than that of the original motion sequences) can be achieved while guaranteeing the effectiveness of the search.

关键词： distance measurement Human motion Time series query analysis Effective firing range Database Content retrieval Categorical Nominal DIMENSIONAL distributed query processing relational query processing

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Failure resilient real-time data federation system 09

Failure resilient real-time data federation system

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Proceedings of the 2009 Spring Simulation Multiconference

作者： Aakanksha Gagrani Brijesh Pillai Srikumar Krishnamoorthy Infosys Technologies Pvt. Ltd.

Data federation systems virtualize access to enterprize data resources by integrating data from disparate and heterogeneous operational data sources in an on-demand and real-time basis. The key challenge of low latency data access in such real-time data federation systems can be addressed by grid based scale-out architecture. However, failure of resources in the grid can pose serious challenges in data federation as the query processing is federated over multiple grid nodes. In such real-time data federation systems, it is often desirable to recover from failure and continue operation rather than repeat the entire process. This paper proposes a decentralized failure-recovery protocol for data federation system using data spaces based architecture. The generic nature of the protocol makes it extensible to applications other than data federation system as well. Moreover, the protocol does not make any assumptions about the availability of any central repository for recovering from failure. We implement the proposed failure recovery protocol in a simulation environment and present the key findings of the study.

关键词： failover grid computing distributed query processing distributed shared memory fault tolerance

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Structure-Preserving Subgraph query Services

Structure-Preserving Subgraph Query Services

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IEEE International Conference on Data Engineering

作者： Zhe Fan Byron Choi Qian Chen Jianliang Xu Haibo Hu Sourav S. Bhowmick Department of Computer Science Hong Kong Baptist University Kowloon Tong China

ISBN: (纸本)9781509020218

Subgraph query (via subgraph isomorphism) is a fundamental and powerful query in various real graph applications. It has actively been investigated for performance enhancements recently. However, due to the high complexity of subgraph query, hosting efficient subgraph query services has been a technically challenging task, because the owners of graph data may not always possess the IT expertise to offer such services and hence may outsource to query service providers (SP). SPs are often equipped with high performance computing utilities (e.g., a cloud) that offer better scalability, elasticity and IT management. Unfortunately, as SPs may not always be trusted, security (such as the confidentiality of messages exchanged) has been recognized as one of the critical attributes of Quality of Services (QoS) [4]. This influences the willingness of both data owners and query clients to use SP's services. Recently, there is a bloom on the research on query processing with privacy preservation, e.g., in the context of relational databases, spatial databases and graph databases. However, up to date, private subgraph query has not yet been studied.

关键词： Legal Services graph data OWNERS query analysis distributed query processing relational query processing Confidentiality graphic library Messages Quality of service CLOUDS Clouds bloom

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An Autonomic in-Network query processing for Urban Sensor Networks

An Autonomic in-Network Query Processing for Urban Sensor Ne...

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IEEE Symposium on Computers and Communication

作者： Marcos A. Carrero Rone I. da Silva Aldri L. dos Santos Carmem S. Hara DINF-Universidade Federal do Parana - UFPR-Parana DTECH - Universidade Federal de Sao Joao del-Rei - UFSJ - Minas Gerais

ISBN: (纸本)9781467371957

The sensing of urban environments usually takes into account the deployment of a large number of devices to measure their environmental attributes, such as temperature, pressure, humidity, luminosity and pollution. In such applications, nearby sensors usually produce similar readings due to their spatial and temporal correlation. In the era of big data, management of collected data requires autonomous and scalable Wireless Sensor Network (WSN) structures. In this paper, we propose an in-network data storage model, called AQPM, that provides efficient processing of both spatial and value-based queries. AQPM is autonomous and scalable. That is, it does not rely on any central entity for neither managing data storage on sensor devices nor for processing queries. Scalability is achieved by grouping sensors with similar readings into clusters, while efficient query processing relies on the concept of repositories. Repositories are sensors that store readings of a set of clusters, and are the only ones that have to be contacted for answering queries. AQPM has been implemented on NS2 simulator and experimental results show that it is more effective than existing approaches.

关键词： distributed query processing relational query processing query analysis reading Scalability Sensors Data Storage Wireless sensor networks WAREHOUSE Sensor networks Data Collection Methods

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Effective XML Data Storage and distributed query Retrieval System

Effective XML Data Storage and Distributed Query Retrieval S...

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The 2010 2nd International Conference on Future Computer and Communication(第二届未来计算机与通信国际会议 ICFCC 2010)

作者： Su-Cheng Haw Chien-Sing Lee Hau-Lee Tong Faculty of Information Technology Multimedia University 63100 Cyberjaya Malaysia

ISBN: (纸本)9781424458219;9781424458240

As XML is gaining its popularity in data exchange over the Web, storing and querying XML data has become an important issue to be addressed especially in terms of support for interoperability and extensibility among various application domains. In order to support this, a dynamic context-driven data exchange architecture is needed. In this paper, we propose an efficient distributed query processing method by partitioning the large native XML repositories into different fragmentations. The query will be evaluated in the query Evaluation Center to determine which query Processor nodes to process the query. The uniqueness of our query Processor lies in the use of a suitable labeling scheme and an efficient indexing scheme which is able to identify parent-child (P-C), ancestor-descendant (A-D) and sibling relationships and consequently retrieve the query result efficiently. Experimental results indicate that our proposed join algorithm, TwigINLAB2 performs about 23％ better compared to TwigStack and 10％ better than TwiglNLABl for all types of queries.

关键词： XML query processing hybrid system indexing labeling distributed data distributed query processing

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Preference-aware Skyline Service Discovery in the Mobile Cloud System

Preference-aware Skyline Service Discovery in the Mobile Clo...

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IEEE International Symposium on Personal, Indoor and Mobile Radio Communications

作者： Yunmin Go Hwangjun Song Division of IT Convergence Engineering POSTECH (Pohang University of Science and Technology) Pohang Republic of Korea Department of Computer Science and Engineering POSTECH (Pohang University of Science and Technology) Pohang Republic of Korea

ISBN: (纸本)9781467362337

Recently, the mobile cloud computing received much attention since it can provide various and powerful services for the mobile user. The service discovery technology in mobile cloud computing is very important to efficiently provide the mobile services. In this paper, we proposed a novel preference-aware skyline service discovery system in the mobile cloud system. The objective of our system is to discover preferable services in the mobile cloud system. Our proposed mobile cloud system is composed of zone-based overlay network. In the overlay network, querying user generates the query with user preference extracted by a Singular Value Decomposition method from the user's service access history. The generated query is sent to the mobile cloud system, and then the query is handled by the distributed skyline query processing mechanism to discover user preferable services with low networking communication cost in the mobile cloud system. We conduct experiments to evaluate the performance of our proposed system.

关键词： Preference-aware Service discovery distributed query processing Mobile cloud system Skyline

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