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Optimizing Large Join Queries in Mediation Systems [chapter]

Ramana Yerneni, Chen Li, Jeffrey Ullman, Hector Garcia-Molina
1999 Lecture Notes in Computer Science  
In this paper, we study the problem of nding feasible and e cient query plans for mediator systems.  ...  In data integration systems, queries posed to a mediator need to be translated into a sequence of queries to the underlying data sources.  ...  In particular, we focus our attention on the kind of queries that are the most expensive in mediation systems, large join queries. W e propose e cient algorithms to nd good plans for such queries.  ... 
doi:10.1007/3-540-49257-7_22 fatcat:fzsqfu67prfmveo7pj4mrxmh4e

Flexible and scalable cost-based query planning in mediators: A transformational approach

José Luis Ambite, Craig A. Knoblock
2000 Artificial Intelligence  
Query planning, the task of generating a cost-efficient plan that computes a user query from the relevant information sources, is central to mediator systems.  ...  dynamic-programming query optimization techniques.  ...  Acknowledgements This work was supported in part by the United States Air Force under contract number  ... 
doi:10.1016/s0004-3702(00)00003-5 fatcat:wftrdfqgozdkldcime6cyazhtu

Evolution of data management systems

Abdelkader Hameurlain
2012 Proceedings of the 14th International Conference on Information Integration and Web-based Applications & Services - IIWAS '12  
in a Large Scale Env.  ...  5.3 Dynamic Query Optimization in Data Grid Systems (1) [Gou 04a/04b/06, Cyb05, Bose 07, Da Sil 06/Porto 06, Liu 08, Soe 05, …] Challenge : How can we describe accurately the system envir environment in  ... 
doi:10.1145/2428736.2428738 dblp:conf/iiwas/Hameurlain12 fatcat:ayoxhgsd7nfcrk6pbph3s6psy4

Decentralized Dynamic Query Optimization based on Mobiles Agents for Large Scale Data Integration Systems

Mohammad Hussein
2012 International Journal of Computer Applications  
The query processing in large scale distributed mediations systems raises new problems and presents real challenges: efficiency of access, communication, confidentiality of access, availability of data  ...  In this paper, we propose an execution model based on mobile agents for the distributed dynamic query optimization.  ...  Mobile query In this sub-section, we propose an execution model based on mobile agents for queries in distributed mediations systems.  ... 
doi:10.5120/9710-4172 fatcat:67fbnnwlnbhk3j4giwlbw2b42u

Sharing Data on the Grid using Ontologies and distributed SPARQL Queries

Andreas Langegger, Martin Blochl, Wolfram Woss
2007 Database and Expert Systems Applications  
Because of the large amount of research undertaken in the field of relational database systems, it is reasonable to apply relational algebra to SPARQL query processors.  ...  In fact, most RDF triple stores are based on relational database systems. In this paper, several concepts are proposed to enable the integration of heterogeneous, distributed data sources with SPARQL.  ...  However, based on response time estimates, the query optimizer will chose alternative plans which enable join operations in relational database systems before data is consumed by the mediator.  ... 
doi:10.1109/dexa.2007.4312934 fatcat:zd5fymlwtncupenp5wc2plw6y4

Sharing Data on the Grid using Ontologies and distributed SPARQL Queries

Andreas Langegger, Martin Blochl, Wolfram Woss
2007 18th International Conference on Database and Expert Systems Applications (DEXA 2007)  
Because of the large amount of research undertaken in the field of relational database systems, it is reasonable to apply relational algebra to SPARQL query processors.  ...  In fact, most RDF triple stores are based on relational database systems. In this paper, several concepts are proposed to enable the integration of heterogeneous, distributed data sources with SPARQL.  ...  However, based on response time estimates, the query optimizer will chose alternative plans which enable join operations in relational database systems before data is consumed by the mediator.  ... 
doi:10.1109/dexa.2007.129 dblp:conf/dexaw/LangeggerBW07 fatcat:oxeiehz73bhgvofdtmzrzc5ydu

Dynamic Query Processing for P2P Data Services in the Cloud [chapter]

Pawel Jurczyk, Li Xiong
2009 Lecture Notes in Computer Science  
The query processing is capable of fully benefiting from all the distributed resources to minimize the query response time and maximize system throughput.  ...  We designed and developed DObjects, a general-purpose P2P-based query and data operations infrastructure that can be deployed in the cloud.  ...  In addition to leveraging traditional distributed query optimization techniques, our optimization is focused on dynamically placing (sub)queries on the system nodes (mediators) to minimize the query response  ... 
doi:10.1007/978-3-642-03573-9_34 fatcat:c6vnebikhjgxzatgpmrrbi2usa

Query optimization in xml-based information integration

Dongfeng Chen, Rada Chirkova, Maxim Kormilitsin, Fereidoon Sadri, Timo J. Salo
2008 Proceeding of the 17th ACM conference on Information and knowledge mining - CIKM '08  
While most of our algorithms are platform-and implementationindependent, we also propose XML-specific optimization techniques that allow for system-level tuning of query processing performance.  ...  We focus on the challenge of efficiency of query evaluation in informationintegrations systems, with the objective of developing queryprocessing strategies that are widely applicable and easy to implement  ...  Consider a system with four information sources and a mediator. Query Q = ΠB,C σP (r 1 s) involves relations r(A, B) and s(A, C) in the mediator schema.  ... 
doi:10.1145/1458082.1458303 dblp:conf/cikm/ChenCKSS08 fatcat:uz2bxwql4jen5brhikxqrs2wia

Fusion queries over internet databases [chapter]

Ramana Yerneni, Yannis Papakonstantinou, Serge Abiteboul, Hector Garcia-Molina
1998 Lecture Notes in Computer Science  
First, we focus on a very wide class of query plans that capture the spirit of many techniques usually considered in existing systems.  ...  We show h o w to e ciently nd good query plans within this large class.  ...  Given this, many mediator systems have incorporated query processing and optimization techniques of distributed databases.  ... 
doi:10.1007/bfb0100977 fatcat:oiykf3e4hfgcpn2fzr3uffkysu

Query Processing and Optimization on the Web

Mourad Ouzzani, Athman Bouguettaya
2004 Distributed and parallel databases  
In this paper, we survey the current research on fundamental problems to efficiently process queries over Web data integration systems.  ...  Uniformly querying those information sources has been extensively investigated. A major challenge relates to query optimization.  ...  HiQIQ (High Quality Information Querying) uses information quality criteria to support query optimization in mediator systems [40] .  ... 
doi:10.1023/b:dapd.0000018574.71588.06 fatcat:qmdqsvtmhzhbpk5atffbwa2msu

DISTRIBUTED QUERY SCHEDULING SERVICE: AN ARCHITECTURE AND ITS IMPLEMENTATION

LING LIU, CALTON PU, KIRILL RICHINE
1998 International Journal of Cooperative Information Systems  
We present the systematic design and development of a distributed query scheduling service DQS in the context of DIOM, a distributed and interoperable query mediation system 26 .  ...  Algorithmically, conventional optimization factors such as join order are considered separately from and re ned by distributed system factors such as data distribution, execution location, heterogeneous  ...  The exponential complexity of the search space makes the use of such optimizers impractical in very large distributed systems.  ... 
doi:10.1142/s0218843098000088 fatcat:vwukm52u4jbvbpbjiakpieyuii

Query processing in multistore systems: an overview

Carlyna Bondiombouy, Patrick Valduriez
2016 International Journal of Cloud Computing  
In Section 3, we review the main query processing techniques for multidatabase systems, based on the mediator-wrapper architecture.  ...  In this paper, we give an overview of query processing in multistore systems.  ...  The approach provides a framework to integrate the data sources cost model into the mediator query optimizer.  ... 
doi:10.1504/ijcc.2016.080903 fatcat:etteedwysbcyfidbaeh7x2lrne

Query processing in multistore systems: an overview

Carlyna Bondiombouy, Patrick Valduriez
2016 International Journal of Cloud Computing  
In Section 3, we review the main query processing techniques for multidatabase systems, based on the mediator-wrapper architecture.  ...  In this paper, we give an overview of query processing in multistore systems.  ...  The approach provides a framework to integrate the data sources cost model into the mediator query optimizer.  ... 
doi:10.1504/ijcc.2016.10001884 fatcat:jpuixv6mxzhmdkuqrmqbgbbl24

An adaptive query execution system for data integration

Zachary G. Ives, Daniela Florescu, Marc Friedman, Alon Levy, Daniel S. Weld
1999 SIGMOD record  
evidence that our techniques result in behavior desirable for a data integration system.  ...  Query processing in data integration occurs over networkbound, autonomous data sources.  ...  In this paper we limit our discussion to select-project-join (conjunctive) queries over this mediated schema.  ... 
doi:10.1145/304181.304209 fatcat:l3jskfrnhnh3lpwxcgmpkuwhb4

The state of the art in distributed query processing

Donald Kossmann
2000 ACM Computing Surveys  
Furthermore, the paper discusses different kinds of distributed systems such as client-server, middleware (multitier), and heterogeneous database systems, and shows how query processing works in these  ...  This paper presents the state of the art of query processing for distributed database and information systems.  ...  mediator can be estimated just as in any other distributed database system because the mediator uses standard, well-understood algorithms to execute joins, group-bys, and so on.  ... 
doi:10.1145/371578.371598 fatcat:qtgrlmt46rdhnicbhdniosdsjq
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