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:
Mar. 08, 2022
Filed:
Jul. 25, 2019
Tencent Technology (Shenzhen) Company Limited, Shenzhen, CN;
Haixiang Li, Shenzhen, CN;
Tencent Technology (Shenzhen) Company Limited, Guangdong, CN;
Abstract
The embodiments of this application provide an uncorrelated subquery optimization method and apparatus, and a storage medium. The method includes determining whether there is an uncorrelated subquery statement in a target clause in a database query statement. In response to the determination that there is the uncorrelated subquery statement in the target clause in the database query statement, the method includes obtaining an estimated number of rows of an execution result set corresponding to the target clause; and determining whether the estimated number of rows is less than a preset threshold. In response to the determination that the estimated number of rows is less than a preset threshold, the method includes executing the uncorrelated subquery statement, and rewriting the target clause according to an execution result set of the uncorrelated subquery statement, to eliminate the uncorrelated subquery statement.