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:
May. 26, 2020
Filed:
Dec. 21, 2017
Futurewei Technologies, Inc., Plano, TX (US);
Kuorong Chiang, Buena Park, CA (US);
Futurewei Technologies, Inc., Plana, TX (US);
Abstract
A server applied to a database management system and a method are provided. By calculating a data skew for a column based on an entropy for the column in a database, storing the data skew to a catalogue in the database, estimating a selectivity for the column by multiplying a first selectivity with the data skew, cardinality estimation in the database management system is improved. By calculating a degree of correlation for two columns in a database, storing the degree of correlation to a catalogue in the database, estimating a selectivity taking into account the degree of correlation, cardinality estimation in the database management system is improved. The improved cardinality estimates in turn improve the query plan generated by the optimizer which leads to better query performance.