发明名称 |
System and method for query optimization using quantile values of a large unordered data set |
摘要 |
A database management system determines, in a single pass over an unordered database, the quantile information. The system sequentially compares each tuple in the data set to a test value, and then selectively inserts the tuple in a test set having a cardinality less than the cardinality of the data set based upon the comparison. The system next uses the quantile information to estimate the number of tuples in the database which satisfy a user-defined predicate to generate an efficient query plan.
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申请公布号 |
US5664171(A) |
申请公布日期 |
1997.09.02 |
申请号 |
US19940227428 |
申请日期 |
1994.04.14 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
AGRAWAL, RAKESH;SWAMI, ARUN NARASIMHA |
分类号 |
G06F17/30;(IPC1-7):G06F17/30;G06F15/00 |
主分类号 |
G06F17/30 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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