发明名称 |
Runtime query optimization for dynamically selecting from multiple plans in a query based upon runtime-evaluated performance criterion |
摘要 |
An apparatus, program product and method perform runtime query optimization during execution of a query to select from among multiple available plans, or implementations, capable of implementing the query. The runtime query optimization utilizes a runtime-derived performance criterion to dynamically select from among multiple query implementations. A performance criterion is dynamically evaluated during execution of at least a portion of a query, and one of a plurality of query implementations defined in the query is selected based upon the dynamically-evaluated performance criterion. Once selected, execution of the query is continued using the selected query implementation.
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申请公布号 |
US2003229639(A1) |
申请公布日期 |
2003.12.11 |
申请号 |
US20020165025 |
申请日期 |
2002.06.07 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
CARLSON DAVID GLENN;KATHMANN KEVIN JAMES;NASH LAWRENCE KENNETH |
分类号 |
G06F17/00;G06F17/30;(IPC1-7):G06F17/00 |
主分类号 |
G06F17/00 |
代理机构 |
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代理人 |
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地址 |
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