Selectivity estimation for conjunctive predicates in the presence of partial knowledge about multivariate data distributions
US8135701B2 · kind B2 · utility
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9Claims
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Key dates
| Filing date | Mar 4, 2008 |
| Grant date | Mar 13, 2012 |
| Priority date | — |
| Expiry date | Apr 20, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99935
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.