Invention Grant
US07873629B1 Dynamic partition enhanced inequality joining using a value-count index
有权
动态分区增强使用数值计数索引的不等式加入
- Patent Title: Dynamic partition enhanced inequality joining using a value-count index
- Patent Title (中): 动态分区增强使用数值计数索引的不等式加入
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Application No.: US10862649Application Date: 2004-06-07
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Publication No.: US07873629B1Publication Date: 2011-01-18
- Inventor: J. Mark Morris , Bhashyam Ramesh
- Applicant: J. Mark Morris , Bhashyam Ramesh
- Applicant Address: US OH Dayton
- Assignee: Teradata US, Inc.
- Current Assignee: Teradata US, Inc.
- Current Assignee Address: US OH Dayton
- Agent Howard Speight
- Main IPC: G06F7/00
- IPC: G06F7/00 ; G06F17/30

Abstract:
Methods, computer programs, and database systems for performing a database query to join a column A and a column B on an inequality condition are disclosed. A database includes value-count indexes for columns A and B. Minimum and a maximum values for A and B are determined, using the value-count indexes for A and B, respectively. The method includes defining three or more sets of values in A and B, relative to the minimum and maximum values for B and A, respectively. The method includes generating one or more Cartesian products between values in A and B. The database query is performed on a set of values in A and a set of values in B to generate a partial query result. The method includes merging one or more Cartesian products and the partial query result.
Public/Granted literature
- US2694583A Laterally and angularly adjustable manifold mounting Public/Granted day:1954-11-16
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