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:
Apr. 05, 2022
Filed:
Jan. 03, 2017
Oracle International Corporation, Redwood Shores, CA (US);
Shasank K. Chavan, Menlo Park, CA (US);
Dina Thomas, Palo Alto, CA (US);
Ajit Mylavarapu, Mountain View, CA (US);
Prashant Gaharwar, San Mateo, CA (US);
Dennis Lui, San Jose, CA (US);
Sheldon A. K. Lewis, Jalisco, MX;
Oracle International Corporation, Redwood Shores, CA (US);
Abstract
Techniques are described herein for reducing the number of redundant evaluations that occur when an expression is evaluated against an encoded column vector by caching results of expression evaluations. When executing a query that includes an expression that references columns for which dictionary-encoded column vectors exist, the database server performs a cost-based analysis to determine which expressions (or sub-expressions) would benefit from caching the expression's evaluation result. For each such expression, the database server performs the necessary computations and caches the results for each of the possible distinct input values. When evaluating an expression for a row with a particular set of input codes, a look-up is performed based on the input code combination to retrieve the pre-computed results of that evaluation from the cache.