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Selectivity estimation for conjunctive predicates in the presence of partial knowledge about multivariate data distributions
Selectivity estimation for conjunctive predicates in the presence of partial knowledge about multivariate data distributions
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机译:在存在有关多元数据分布的部分知识的情况下,对联合谓词的选择性估计
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摘要
A method for consistent selectivity estimation based on the principle of maximum entropy (ME) is provided. The method efficiently exploits all available information and avoids the bias problem. In the absence of detailed knowledge, the ME approach reduces to standard uniformity and independence assumptions. The disclosed method, based on the principle of ME, is used to improve the optimizer's cardinality estimates by orders of magnitude, resulting in better plan quality and significantly reduced query execution times.
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