发明名称 |
EXPRESSION REPLACEMENT IN VIRTUAL COLUMNS |
摘要 |
Techniques are described herein for replacing a part of an expression in a query to a database with a virtual column. A virtual column is defined by the database to contain results of a defining expression. A part of an expression in a query is replaced with a virtual column whose defining expression is equal to the part of the expression in the query. The part of an expression in a query can be the entire expression. When an expression in a query can be replaced with more than one replacement expression involving virtual columns, the replacement expression with the least cost of query processing is selected.
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申请公布号 |
US2009150366(A1) |
申请公布日期 |
2009.06.11 |
申请号 |
US20070951918 |
申请日期 |
2007.12.06 |
申请人 |
ORACLE INTERNATIONAL CORPORATION |
发明人 |
BASU SUBHRANSU;BEDI HARMEEK SINGH |
分类号 |
G06F17/30 |
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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