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

  • 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

OWNER

VARCHAR2(128)

NOT NULL

Owner of the rewrite equivalence

NAME

VARCHAR2(128)

NOT NULL

Name of the rewrite equivalence

SOURCE_STMT

CLOB

Source statement of the rewrite equivalence

DESTINATION_STMT

CLOB

Destination of the rewrite equivalence

REWRITE_MODE

VARCHAR2(10)

Rewrite mode of the rewrite equivalence:

  • DISABLED

  • TEXT_MATCH

  • GENERAL

  • RECURSIVE

See Also:

  • “DBA_REWRITE_EQUIVALENCES”

  • “USER_REWRITE_EQUIVALENCES”


数据运维技术 » Oracle 视图 ALL_REWRITE_EQUIVALENCES 官方解释,作用,如何使用详细说明