本站中文解释
UNDO_MANAGEMENT参数用于控制undo方法的文件生成方式。
UNDO_MANAGEMENT的默认值为AUTO，表示系统会根据数据库参数和空间要求来决定是使用带有管理器（MANAGED）还是自动生成管理（AUTO）模式生成undo方法文件。
如果想正确设置UNDO_MANAGEMENT参数，需要根据系统的情况调整，重要的原则是要尽量使用自动生成模式。如果要使用带有管理器模式，就需要更多的undo空间。同时，如果想使用自动生成模式，还需要考虑系统的资源，保证系统的响应时间。
官方英文解释
UNDO_MANAGEMENT specifies which undo space management mode the system should use.
| Property | Description |
|---|---|
|
Parameter type |
String |
|
Syntax |
|
|
Default value |
|
|
Modifiable |
No |
|
Modifiable in a PDB |
Yes |
|
Basic |
No |
|
Oracle RAC |
Multiple instances must have the same value. |
When UNDO_MANAGEMENT is set to AUTO, the instance starts in automatic undo management mode. In manual undo management mode, undo space is allocated externally as rollback segments.
Note:
In a CDB, the UNDO_MANAGEMENT initialization parameter must be set to AUTO, and an undo tablespace is required to be created to manage the undo data.
See Also:
-
Oracle Database
Administrator’s Guide for more information about this parameter -
Oracle Database
Administrator’s Guide for more information about managing undo data
