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. 05, 2020
Filed:
Sep. 15, 2017
Tableau Software, Inc., Seattle, WA (US);
Tableau Software, Inc., Seattle, WA (US);
Abstract
A database engine receives a human-readable database query that includes a subquery, and parses the database query to build an operator tree. The operator tree includes a subtree corresponding to the subquery. The database engine estimates the number of rows that will accessed when the subtree is executed and estimates the fraction of the cardinality of rows that will be filtered out by subsequent operations in the operator tree. In accordance with a determination that the estimated fraction exceeds a first threshold, the database engine inserts a domain constraint into the subtree that restricts rows retrieved by execution of the subtree, thereby forming a modified operator tree. The database engine executes the modified operator tree to form a final result set corresponding to the database query and returns the final result set.