Oracle 视图 ALL_REWRITE_EQUIVALENCES 官方解释,作用,如何使用详细说明
本站中文解释
ALL_REWRITE_EQUIVALENCES视图主要用于收集存储在数据库中的等价规则,Oracle 数据库中的等价规则用于将不同的 SQL 语句重写为等效的 SQL 语句,这有助于 Oracle 数据库改善 SQL 语句的可读性、减少 SQL 语句在执行时产生的计算量、提高 SQL 语句的执行效率。
使用ALL_REWRITE_EQUIVALENCES视图查看等价规则,需要首先连接数据库,然后执行如下查询:
SELECT Eq.Owner, Eq.Equivalent, Rw.Search_String
FROM All_Rewrite_Equivalences Eq
join All_Rewrite_Rules Rw
on (Eq.Owner = Rw.Owner
and Eq.Rewrite_Equivalence_Name = Rw.Rewrite_Equivalence_Name)
ORDER BY Eq.Owner, Eq.Equivalent;
该语句主要用于查询等价规则的所有者、等价规则的等价SQL语句及匹配该等价规则的搜索字符串。
官方英文解释
ALL_REWRITE_EQUIVALENCES
describes the rewrite equivalences accessible to the current user.
Related Views
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DBA_REWRITE_EQUIVALENCES
describes all rewrite equivalences in the database. -
USER_REWRITE_EQUIVALENCES
describes the rewrite equivalences owned by the current user.
Column | Datatype | NULL | Description |
---|---|---|---|
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Owner of the rewrite equivalence |
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Name of the rewrite equivalence |
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Source statement of the rewrite equivalence |
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Destination of the rewrite equivalence |
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Rewrite mode of the rewrite equivalence:
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See Also:
-
“DBA_REWRITE_EQUIVALENCES”
-
“USER_REWRITE_EQUIVALENCES”