Oracle 视图 V$IO_OUTLIER 官方解释，作用，如何使用详细说明
本站中文解释
V$IO_OUTLIER视图是Oracle提供的一个列出FSIO（文件系统I/O）异常的视图。它可以用来检测和诊断磁盘I/O的异常性能。
每一行记录着一次文件I/O操作，此操作的平均每秒字节数比它舍入的尺寸低了指定的阈值。通过V$IO_OUTLIER视图，DBA可以检测及时地发现应用中的一些I/O瓶颈。
使用方式：
1、首先查询V$IO_OUTLIER 视图，查看是否有异常的数据：
SELECT * FROM V$IO_OUTLIER;
2、如果查询结果存在异常的记录，可以使用下面这条SQL语句，查看这些异常数据在资料库中查找相应的文件：
SELECT *
FROM DBA_DATA_FILES
WHERE FILE_ID IN (SELECT FILE_NO FROM V$IO_OUTLIER);
3、最后，根据查询结果，可以采取相应的措施，比如优化SQL，减少磁盘I/O等，解决性能问题。
官方英文解释
V$IO_OUTLIER contains entries corresponding to I/Os that have taken a long time (more than 500 ms) to complete. Use this view to see if there any occasional delays in serving disk I/O requests by the storage subsystem.
| Column | Datatype | Description |
|---|---|---|
|
|
|
I/O function name of the delayed I/O |
|
|
|
Size of the I/O in bytes |
|
|
|
Wait event name that was used to track the I/O |
|
|
|
Name of the file to which the I/O was targeted |
|
|
|
Time taken to complete the I/O (in milliseconds) |
|
|
|
For Oracle ASM, the name of the first disk to which the I/O was issued |
|
|
|
Latency seen on the first disk (in milliseconds) |
|
|
|
For Oracle ASM, the name of the second disk to which the I/O was issued |
|
|
|
Latency seen on the second disk (in milliseconds) |
|
|
|
For Oracle ASM, the name of the third disk to which the I/O was issued |
|
|
|
Latency seen on the third disk (in milliseconds) |
|
|
|
The ID of the container to which the data pertains. Possible values include:
|
See Also:
-
“V$KERNEL_IO_OUTLIER”
-
“V$LGWRIO_OUTLIER”
