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. 27, 2008
Filed:
Nov. 27, 2002
Andrew Witkowski, Foster City, CA (US);
Lei Sheng, San Mateo, CA (US);
Andrew Witkowski, Foster City, CA (US);
Lei Sheng, San Mateo, CA (US);
Oracle International Corporation, Redwood Shores, CA (US);
Abstract
Query rewrite techniques are provided for rewriting an aggregate query with multiple groupings using multiple summary tables. The rewrite is accomplished by expanding the aggregate query into an equivalent UNION ALL query with multiple subqueries, each containing a single grouping. One or more of the subqueries is then rewritten to reference a summary table. Thus, a grouping of an aggregate query is derived by executing a subquery that either scans the summary table for the grouping, like in the exact-match mode, or by performing a roll-up operation, like in the roll-up mode. In addition, if the grouping of some of the subqueries cannot be derived from a summary table, subqueries are combined into another subquery that computes groupings from the base tables of the aggregate query.