Oracle教程 2023-02-24

Oracle 视图 V$CLEANUP_PROCESS 官方解释，作用，如何使用详细说明

Oracle视图V$CLEANUP_PROCESS显示所有的Cleanup Task的详细信息，它包括当前正在执行的和待执行的事务，它在分析数据库中的性能和潜在的问题时非常有用。

使用V$CLEANUP_PROCESS视图的第一步是执行一个SELECT from V$CLEANUP_PROCESS命令，以获取列表，其中列出了当前正在执行和准备执行的所有可能的清理任务：

SELECT * FROM V$CLEANUP_PROCESS;

这条命令将会返回一个表，该表显示所有可用的清理流程，它们的名称、执行操作、持续时间以及潜在影响。

如果要查看特定清理任务的详细信息，可以使用类似下面的语句：

SELECT * FROM V$CLEANUP_PROCESS WHERE NAME= ‘Cleanup Task1’;

使用此语句，可以查看Cleanup Task1的详细信息，即它的持续时间、预期的影响等。

此外，也可以使用类似于下面的语句按类型筛选所有可执行的清理任务：

SELECT * FROM V$CLEANUP_PROCESS WHERE TYPE = ‘TYPE1’;

此语句将返回具有特定类型的所有清理任务的详细信息。

V$CLEANUP_PROCESS provides information on the PMON processes.

Column	Datatype	Description
`NAME`	`VARCHAR2(5)`	Name of the cleanup process (PMON, CLMN, CL**)
`PADDR`	`RAW(8)`	Process pointer for the cleanup process (can join with `V$PROCESS`)
`SADDR`	`RAW(8)`	Session pointer for the cleanup process (can join with `V$SESSION`)
`STATE`	`VARCHAR2(4)`	Cleanup process state: `IDLE`: Not currently performing cleanup `BUSY`: Currently performing cleanup
`DEAD_IN_CLEANUP`	`RAW(8)`	Pointer to the root of the tree in cleanup (can join with `ROOT_ADDR` in `V$DEAD_CLEANUP`)
`CLEANUP_TIME`	`NUMBER`	If `STATE` = `BUSY`, the time spent in the current cleanup attempt (in seconds). Otherwise, `0`.
`TIME_SINCE_LAST_CLEANUP`	`NUMBER`	If `STATE` = `IDLE`, time since last needed to perform cleanup (in seconds). Otherwise, `0`.
`NUM_CLEANED`	`NUMBER`	Number of trees cleaned up by the cleanup process. Increased by one every time a root tree is attempted.
`CON_ID`	`NUMBER`	The ID of the container to which the data pertains. Possible values include: `0`: This value is used for rows containing data that pertain to the entire multitenant container database (CDB). This value is also used for rows in non-CDBs. `1`: This value is used for rows containing data that pertain to only the root n: Where n is the applicable container ID for the rows containing data