Invention Grant
- Patent Title: Automatically determining optimization frequencies of queries with parameter markers
- Patent Title (中): 使用参数标记自动确定查询的优化频率
-
Application No.: US12125146Application Date: 2008-05-22
-
Publication No.: US07987178B2Publication Date: 2011-07-26
- Inventor: Fabian Hueske , Volker Gerhard Markl
- Applicant: Fabian Hueske , Volker Gerhard Markl
- Applicant Address: US NY Armonk
- Assignee: International Business Machines Corporation
- Current Assignee: International Business Machines Corporation
- Current Assignee Address: US NY Armonk
- Agency: Schmeiser, Olsen & Watts
- Main IPC: G06F17/30
- IPC: G06F17/30

Abstract:
A method and system for automatically determining optimization frequencies of queries having one or more parameter markers. Execution plans for a query are generated and each plan is associated with one or more bind value sets. An optimization frequency is selected based on differences between pairs of execution costs where one execution cost of a pair is a cost of executing the query with a bind value set via a first execution plan and the other execution cost of the pair is a cost of optimally executing the query with the bind value set via a second execution plan. The differences are based on maximum selectivity or cardinality distances associated with the bind value sets. If none of the differences exceeds a predefined value, the query is optimized once. If at least one of the differences exceeds the predefined value, the query is reoptimized each time the query is executed.
Public/Granted literature
- US20080222092A1 AUTOMATICALLY DETERMINING OPTIMIZATION FREQUENCIES OF QUERIES WITH PARAMETER MARKERS Public/Granted day:2008-09-11
Information query