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. 17, 2012
Filed:
Oct. 29, 2004
Jinmei Shen, Rochester, MN (US);
Hao Wang, Rochester, MN (US);
Jinmei Shen, Rochester, MN (US);
Hao Wang, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method, apparatus, system, and signal-bearing medium that, in an embodiment, collect previous and current statistics based on previous and current access plans, respectively, and a query. The previous and current statistics are compared in response to an event, and the differences between the previous and current statistics are presented. In various embodiments, the event may be a change to logic in a database management system that performs the query, a degradation in performance of the query, or a user request. In various embodiments, the difference may be a change to the previous access plan that causes performance degradation of the query, such as missing an index. The previous access plan is copied into the current access plan if an estimated processing time for the current access plan is greater than an estimated processing time for the previous access plan. The current access plan is used to perform the query.