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:
Jan. 05, 2010
Filed:
Mar. 08, 2007
Hong Su, Foster City, CA (US);
Rafi Ahmed, Fremont, CA (US);
Allison Lee, Sunnyvale, CA (US);
Mohamed Zait, San Jose, CA (US);
Thierry Cruanes, Foster City, CA (US);
Hong Su, Foster City, CA (US);
Rafi Ahmed, Fremont, CA (US);
Allison Lee, Sunnyvale, CA (US);
Mohamed Zait, San Jose, CA (US);
Thierry Cruanes, Foster City, CA (US);
Oracle International Corporation, Redwood Shores, CA (US);
Abstract
Under a type of query transformation referred to herein as join factorization, the branches of an UNION/UNION ALL query that join a common table are combined to reduce accesses to the common table. The transformation can be expressed as (Tjoin T) union all (Tjoin T)=Tjoin (Tunion all T), where T, Tand Tare three tables. A given query may be rewritten in many alternate ways using join factorization. Evaluating each alternative can be expensive. Therefore, the alternatives are generated and evaluated in a way that minimizes the cost of evaluating the alternatives.