The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 21, 2017
Filed:
Oct. 27, 2008
Vinay Deolalikar, Cupertino, CA (US);
Choudur Lakshminarayan, Austin, TX (US);
Hernan Laffitte, Mountain View, CA (US);
Vinay Deolalikar, Cupertino, CA (US);
Choudur Lakshminarayan, Austin, TX (US);
Hernan Laffitte, Mountain View, CA (US);
Hewlett Packard Enterprise Development LP, Houston, TX (US);
Abstract
In a method for generating a query plan for estimating a number of unique entry counts of an attribute in a database, a sample of entries in the database is identified, at least one of a sampling percent and a coefficient of variance of the entries in the sample is identified, and a skewness of the entries in the sample is calculated. In addition, at least one of a plurality of estimators is selected based upon the skewness of the entries and at least one of the sampling percent and the coefficient of variance of the entries in the sample. Moreover, a query plan is generated from the selected at least one of the plurality of estimators. A query optimizer for performing the method is provided.