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:
Aug. 30, 2022
Filed:
Dec. 24, 2019
Oracle International Corporation, Redwood Shores, CA (US);
Sabina Petride, Tracy, CA (US);
Mohamed Ziauddin, Pleasanton, CA (US);
Praveen T.J. Kumar, Nashua, NH (US);
ORACLE INTERNATIONAL CORPORATION, Redwood Shores, CA (US);
Abstract
Techniques are provided for bitmap-based computation of a COUNT(DISTINCT) function, where the bitmaps are generated based on ranks of target expression values. According to an embodiment, the ranks are computed using the DENSE_RANK function. The bitmaps may be maintained in a materialized view. Bitmap data that represents the ranks for target expression values occurring in data for a given group is divided across multiple bucket bitmaps, each corresponding to a distinct sub-range of the ranks. According to an embodiment, target expression value ranks are computed relative to partitions of the target expression values. When these partitions correspond to a subset (not necessarily strict) of the target query grouping keys for a query rewrite, the resulting bitmaps allow computation of multiple levels of aggregation from the single set of bitmaps.