发明授权
- 专利标题： Predictable query execution through early materialization
- 专利标题（中）： 通过早期实现可预测的查询执行
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申请号： US11388934申请日： 2006-03-24
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公开(公告)号： US07490110B2公开(公告)日： 2009-02-10
- 发明人: Stephan Eberhard Ewen , Holger Kache , Guy Maring Lohman , Volker Gerhard Markl , Vijayshankar Raman
- 申请人： Stephan Eberhard Ewen , Holger Kache , Guy Maring Lohman , Volker Gerhard Markl , Vijayshankar Raman
- 申请人地址： US NY Armonk
- 专利权人： International Business Machines Corporation
- 当前专利权人： International Business Machines Corporation
- 当前专利权人地址： US NY Armonk
- 代理商 Duke W. Yee; Doug H. Lefeve; Gerald H. Glanzman
- 主分类号： G06F17/30
- IPC分类号： G06F17/30
摘要：
A method for predictable query execution through early materialization is provided. The method deals with the problem of cardinality misestimation in query execution plans, by pre-executing sub-plans on a query execution plan that have questionable estimates and collecting statistics on the output of these sub-plans. If needed, the overall query execution plan is changed in light of these statistics, before optimizing and executing the remainder of the query.