Oracle 视图 DBA_HIST_LATCH_PARENT 官方解释，作用，如何使用详细说明
本站中文解释
Oracle视图DBA_HIST_LATCH_PARENT用于记录当前活动的钩子与其父进程之间的关系。其中包括以下列：
– PARENT_LATCH_HANDLE：父进程句柄。
– LATCH：当前活动的钩子。
– CHILD_COUNT：使用该钩子的子进程数。
– SHARE_COUNT：该钩子共享的子进程数。
通过Oracle视图DBA_HIST_LATCH_PARENT，可以对系统正在使用的钩子进行监控，以便确定系统的内部状态，并减少存在性能问题的可能性，例如死锁。
使用Oracle视图DBA_HIST_LATCH_PARENT的方法如下：
§ SELECT * FROM dba_hist_latch_parent;
官方英文解释
DBA_HIST_LATCH_PARENT displays historical statistics about parent latches.
This view contains snapshots of V$LATCH_PARENT.
| Column | Datatype | NULL | Description |
|---|---|---|---|
|
|
|
|
Unique snapshot ID |
|
|
|
|
Database ID for the snapshot |
|
|
|
|
Instance number for the snapshot |
|
|
|
|
Latch hash |
|
|
|
|
Latch name |
|
|
|
|
Latch level |
|
|
|
Number of times the latch was requested in willing-to-wait mode |
|
|
|
|
Number of times the latch was requested in willing-to-wait mode and the requester had to wait |
|
|
|
|
Number of times a willing-to-wait latch request resulted in a session sleeping while waiting for the latch |
|
|
|
|
Number of times a latch was requested in no-wait mode |
|
|
|
|
Number of times a no-wait latch request did not succeed (that is, missed) |
|
|
|
|
Number of willing-to-wait latch requests which missed the first try but succeeded while spinning |
|
|
|
|
These columns have been deprecated and are present only for compatibility with previous releases of Oracle. No data is accumulated for these columns; they will always have a value of zero. |
|
|
|
|
Elapsed time spent waiting for the latch (in microseconds) |
|
|
|
|
The database ID of the PDB for the sampled session |
|
|
|
|
The ID of the container that
|
See Also:
“V$LATCH_PARENT”
