发明授权
- 专利标题： Method for executing a query having multiple distinct key columns
- 专利标题（中）： 执行具有多个不同键列的查询的方法
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申请号： US10320909申请日： 2002-12-17
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公开(公告)号： US07487140B2公开(公告)日： 2009-02-03
- 发明人: Yao-Ching Chen , You-Chin Fuh , Allan B. Lebovitz , Li-Mey Lee , Fen-Ling Lin , Lee-Chin Hsu Liu , Yun Wang , Binghua Zhen
- 申请人： Yao-Ching Chen , You-Chin Fuh , Allan B. Lebovitz , Li-Mey Lee , Fen-Ling Lin , Lee-Chin Hsu Liu , Yun Wang , Binghua Zhen
- 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
- 代理机构： Sawyer Law Group LLP
- 主分类号： G06F17/30
- IPC分类号： G06F17/30
摘要：
A method for executing a query to access data stored in a database, wherein the query includes a plurality of DISTINCT keys, is disclosed. The method of the present invention includes providing a first DISTINCT operation on a first DISTINCT key, storing data fetched from the first DISTINCT operation in a master workfile if more than one sort process is needed to execute the query, and utilizing the master workfile to perform subsequent DISTINCT operations for the other DISTINCT keys.