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Query Processing and Optimization
2000The ultimate purpose of a data warehouse is to support queries by end users who want to analyze the available information for an organization. However, from a more abstract point of view, queries are not only processed at the data warehouse back end.
Panos Vassiliadis +3 more
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Query Optimization in Oracle 12c Database In-Memory
Proceedings of the VLDB Endowment, 2015Traditional on-disk row major tables have been the dominant storage mechanism in relational databases for decades. Over the last decade, however, with explosive growth in data volume and demand for faster analytics, has come the recognition that a ...
Dinesh Das +8 more
semanticscholar +1 more source
ACM SIGMOD Record, 1986
In some recently proposed extensions to relational database systems as well as in deductive databases, a database system is presented with a collection of queries to process instead of just one. It is an interesting problem then, to come up with algorithms that process these queries together instead of one query at a time.
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In some recently proposed extensions to relational database systems as well as in deductive databases, a database system is presented with a collection of queries to process instead of just one. It is an interesting problem then, to come up with algorithms that process these queries together instead of one query at a time.
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Optimization and evaluation of disjunctive queries
IEEE Transactions on Knowledge and Data Engineering, 2000It is striking that the optimization of disjunctive queries-i.e. those which contain at least one OR-connective in the query predicate-has been vastly neglected in the literature, as well as in commercial systems. In this paper, we propose a novel technique, called bypass processing, for evaluating such disjunctive queries.
Claussen, Jens +4 more
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Progressive Query Optimization for Federated Queries
2006Database Management Systems (DBMS) perform query plan selection by mathematically modeling the execution cost of candidate execution plans and choosing the cheapest query execution plan (QEP) according to that cost model. The cost model requires accurate estimates of the sizes of intermediate results of all steps in the QEP.
Vijayshankar Raman +3 more
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Distributed Query Optimization by Query Trading
2004Large-scale distributed environments, where each node is completely autonomous and offers services to its peers through external communication, pose significant challenges to query processing and optimization. Autonomy is the main source of the problem, as it results in lack of knowledge about any particular node with respect to the information it can ...
Fragkiskos Pentaris, Yannis Ioannidis
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Proceedings of 16th International Conference on Data Engineering (Cat. No.00CB37073), 2002
We demonstrate a Web Query Optimizer (WQO) within an architecture of mediators and wrappers, for WebSources of limited capability in a wide area environment. The WQO has several innovative features, including a CBR (capability based rewriting) tool, an enhanced randomized relational optimizer extended to a Web environment, and a WebWrapper cost model ...
Louiqa Raschid +4 more
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We demonstrate a Web Query Optimizer (WQO) within an architecture of mediators and wrappers, for WebSources of limited capability in a wide area environment. The WQO has several innovative features, including a CBR (capability based rewriting) tool, an enhanced randomized relational optimizer extended to a Web environment, and a WebWrapper cost model ...
Louiqa Raschid +4 more
openaire +1 more source
Continuous Cloud-Scale Query Optimization and Processing
Proceedings of the VLDB Endowment, 2013Massive data analysis in cloud-scale data centers plays a crucial role in making critical business decisions. High-level scripting languages free developers from understanding various system trade-offs, but introduce new challenges for query optimization.
Nicolas Bruno, Sapna Jain, Jingren Zhou
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Optimizing a Query by Transformation and Expansion
2017In the biomedical sector not only the amount of information produced and uploaded into the web is enormous, but also the number of sources where these data can be found. Clinicians and researchers spend huge amounts of time on trying to access this information and to filter the most important answers to a given question.
Alexander Knurr +8 more
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Semantic query optimization for object queries
1995Semantic query optimization is an approach to query optimization that utilizes semantic knowledge to reformulate a query into one that would generate the same set of answers in a more efficient way. The semantic query optimization becomes more important in OODB systems where object queries are complex due to the presence of object-oriented concepts ...
Young-Whun Lee, Suk I. Yoo
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