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Algebraic query optimization for distributed top-k queries
Informatik - Forschung und Entwicklung, 2007Distributed top-k query processing is increasingly becoming an essential functionality in a large number of emerging application classes. This paper addresses the efficient algebraic optimization of top-k queries in wide-area distributed data repositories where the index lists for the attribute values (or text terms) of a query are distributed across a
Neumann, T., Michel, S.
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ACM SIGMOD Record, 1996
The strength of commercial query optimizers like DB2 comes from their ability to select an optimal order by generating all equivalent reorderings of binary operators. However, there are no known methods to generate all equivalent reorderings for a SQL query containing joins, outer joins, and groupby aggregations.
Piyush Goel, Bala Iyer
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The strength of commercial query optimizers like DB2 comes from their ability to select an optimal order by generating all equivalent reorderings of binary operators. However, there are no known methods to generate all equivalent reorderings for a SQL query containing joins, outer joins, and groupby aggregations.
Piyush Goel, Bala Iyer
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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 ...
V. Zadorozhny +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 ...
V. Zadorozhny +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.
Stephan Ewen +3 more
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Proceedings of the 3rd VLDB Workshop on In-Memory Data Mangement and Analytics, 2015
In the recent past, in-memory distributed database management systems have become increasingly popular to manage and query huge amounts of data. For an in-memory distributed database like MemSQL, it is imperative that the analytical queries run fast.
Rajkumar Sen +2 more
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In the recent past, in-memory distributed database management systems have become increasingly popular to manage and query huge amounts of data. For an in-memory distributed database like MemSQL, it is imperative that the analytical queries run fast.
Rajkumar Sen +2 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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Multiobjective query optimization
Proceedings of the twentieth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems, 2001The optimization of queries in distributed database systems is known to be subject to delicate trade-offs. For example, the Mariposa database system allows users to specify a desired delay-cost tradeoff (that is, to supply a decreasing function u(d), specifying how much the user is willing to pay in order to receive the query results within time d ...
Christos H. Papadimitriou +1 more
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Proceedings of the 2007 ACM SIGMOD international conference on Management of data, 2007
Managing uncertain data using probabilistic frameworks has attracted much interest lately in the database literature, and a central computational challenge is probabilistic inference. This paper presents a broad class of aggregate queries, called MPF queries, inspired by the literature on probabilistic inference in statistics and machine learning.
Héctor Corrada Bravo +1 more
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Managing uncertain data using probabilistic frameworks has attracted much interest lately in the database literature, and a central computational challenge is probabilistic inference. This paper presents a broad class of aggregate queries, called MPF queries, inspired by the literature on probabilistic inference in statistics and machine learning.
Héctor Corrada Bravo +1 more
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Parallelizing query optimization
Proceedings of the VLDB Endowment, 2008Many commercial RDBMSs employ cost-based query optimization exploiting dynamic programming (DP) to efficiently generate the optimal query execution plan. However, optimization time increases rapidly for queries joining more than 10 tables.
Wook-Shin Han +4 more
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2006
Determining the best execution plan for a spatial query requires tools for measuring (more precisely, estimating) the number of (spatial) data items that are retrieved by a query as well as its cost, in terms of I/O and CPU effort. As in traditional databases, spatial query optimization tools include cost-based models, exploiting analytical formulae ...
Yannis Manolopoulos +3 more
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Determining the best execution plan for a spatial query requires tools for measuring (more precisely, estimating) the number of (spatial) data items that are retrieved by a query as well as its cost, in terms of I/O and CPU effort. As in traditional databases, spatial query optimization tools include cost-based models, exploiting analytical formulae ...
Yannis Manolopoulos +3 more
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