Results 281 to 290 of about 482,214 (330)
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ACM Computing Surveys, 1984
In this paper, various techniques for optimizing queries in distributed databases are presented. Although no attempt is made to cover all proposed algorithms on this topic, quite a few ideas extracted from existing algorithms are outlined. It is hoped that large-scale experiments will be conducted to verify the usefulness of these ideas and that they ...
Clement T. Yu, C. C. Chang
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In this paper, various techniques for optimizing queries in distributed databases are presented. Although no attempt is made to cover all proposed algorithms on this topic, quite a few ideas extracted from existing algorithms are outlined. It is hoped that large-scale experiments will be conducted to verify the usefulness of these ideas and that they ...
Clement T. Yu, C. C. Chang
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Proceedings. 20th International Conference on Data Engineering, 2005
XQuery is starting to gain significant traction as a language for querying and transforming XML data. It is used in a variety of different products. Examples to date include XML database systems, XML document repositories, XML data integation, workflow systems, and publish and subscribe systems.
Daniela Florescu, Donald Kossmann
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XQuery is starting to gain significant traction as a language for querying and transforming XML data. It is used in a variety of different products. Examples to date include XML database systems, XML document repositories, XML data integation, workflow systems, and publish and subscribe systems.
Daniela Florescu, Donald Kossmann
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1995
An approach to query processing in object-oriented stores supporting physical data independence is proposed in this Chapter. In particular, the problem of query optimisation (i e finding efficient execution plans for declarative queries) is investigated. A set of rewrite rules has been defined in order to allow an algebraic optimisation phase.
Rabitti F, Benedetti L, Demi F
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An approach to query processing in object-oriented stores supporting physical data independence is proposed in this Chapter. In particular, the problem of query optimisation (i e finding efficient execution plans for declarative queries) is investigated. A set of rewrite rules has been defined in order to allow an algebraic optimisation phase.
Rabitti F, Benedetti L, Demi F
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Processing Implication on Queries
IEEE Transactions on Software Engineering, 1989The ability to quickly determine how to derive a given query from a set of prestored fragments is highly demanded in many database applications, especially in distributed database systems, where the communication cost is a major concern. The main difficulty in solving this problem lies in the implication problem given two predicates σQ and σT, can σQ ...
Sun, Xian-he +2 more
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Query Relaxation in Cooperative Query Processing
2009This chapter explores new trends of query relaxation strategies that allow to implement a cooperative query processing paradigm. This new paradigm is based on the belief that the user has an idea of what he/she wants and the system has to automatically lead him/her to formulate meaningful queries by relaxing query constraints.
D'Ulizia Arianna +2 more
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Proceedings of the VLDB Endowment, 2019
Many applications ingest data in an intermittent, yet largely predictable, pattern. Existing systems tend to ignore how data arrives when making decisions about how to update (or refresh) an ongoing query. To address this shortcoming we propose a new query processing paradigm, Intermittent Query Processing (IQP), that bridges query execution and ...
Dixin Tang +4 more
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Many applications ingest data in an intermittent, yet largely predictable, pattern. Existing systems tend to ignore how data arrives when making decisions about how to update (or refresh) an ongoing query. To address this shortcoming we propose a new query processing paradigm, Intermittent Query Processing (IQP), that bridges query execution and ...
Dixin Tang +4 more
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Query Processing in Spatial-Query-by-Sketch
Journal of Visual Languages & Computing, 1997Abstract Spatial-Query-by-Sketch is the design of a query language for geographic information systems. It allows a user to formulate a spatial query by drawing the desired configuration with a pen on a touch-sensitive computer screen and translates this sketch into a symbolic representation that can be processed against a geographic database.
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Computer, 2007
Sensors produce large streams of raw events while instrumenting environments such as computer systems, communications networks, physical spaces, and human organizations. Extracting meaningful and actionable information from these events, however, remains a challenge.
George Cybenko, Vincent H. Berk
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Sensors produce large streams of raw events while instrumenting environments such as computer systems, communications networks, physical spaces, and human organizations. Extracting meaningful and actionable information from these events, however, remains a challenge.
George Cybenko, Vincent H. Berk
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AvantGraph query processing engine
Proceedings of the VLDB Endowment, 2022We demonstrate AvantGraph, a graph query processing engine developed by the Database group at TU Eindhoven. Designed for efficient processing of both subgraph matching and navigational graph queries, AvantGraph encompasses innovation in three key areas: the planner, the cardinality estimator, and the execution ...
Wilco van Leeuwen +4 more
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Process Instance Query Language and the Process Querying Framework
2021The use of Business Process Management Systems (BPMSs) allows companies to manage the data that flows through process models (business instances) and to monitor all the information and actions concerning a process execution. In general, the retrieval of this information is used not only to measure whether the process works as expected but also to ...
Pérez Álvarez, José Miguel +4 more
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