Oracle教程 2023-02-23

Oracle 视图 ALL_EXPRESSION_STATISTICS 官方解释，作用，如何使用详细说明

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Oracle视图ALL_EXPRESSION_STATISTICS描述一个用户所有的表达式统计信息。它会显示一个表达式的微调信息，如它被编译过微调次数，该表达式的环境名等。

使用ALL_EXPRESSION_STATISTICS视图需要具有足够的privilege，这些privileges可以通过grant statement来被授权，具体语句如下：

GRANT SELECT ON sys.ALL_EXPRESSION_STATISTICS TO {user};

ALL_EXPRESSION_STATISTICS provides expression usage tracking statistics for tables that are accessible to the current user.

Related Views

DBA_EXPRESSION_STATISTICS provides expression usage tracking statistics for all the tables in the database.
USER_EXPRESSION_STATISTICS provides expression usage tracking statistics for tables owned by the current user. This view does not display the OWNER column.

Column	Datatype	NULL	Description
`OWNER`	`VARCHAR2(128)`	`NOT NULL`	Owner of the table
`TABLE_NAME`	`VARCHAR2(128)`	`NOT NULL`	Name of the table contained in the expression
`EXPRESSION_ID`	`NUMBER`		Expression ID of the current expression
`SNAPSHOT`	`VARCHAR2(10)`		Type of snapshot for the expression: `LATEST`: Latest snapshot `CUMULATIVE`: Cumulative snapshot `WINDOW`: Window snapshot
`EVALUATION_COUNT`	`NUMBER`		Number of times the expression has been evaluated
`FIXED_COST`	`NUMBER`	`NOT NULL`	Optimizer fixed cost of evaluating the expression
`DYNAMIC_COST`	`NUMBER`		Optimizer dynamic cost of evaluating the expression
`EXPRESSION_TEXT`	`VARCHAR2(4000)`	`NOT NULL`	Text of the expression
`CREATED`	`DATE`	`NOT NULL`	Time this expression is first evaluated
`LAST_MODIFIED`	`DATE`		Time this expression is last evaluated