Oracle 参数 CPU_MIN_COUNT 官方解释，作用，如何配置最优化建议
本站中文解释
CPU_MIN_COUNT是Oracle 10g及以上版本的参数，它的作用是指定了应用到当前实例的最小逻辑CPU数量，实际上指的就是Oracle可以使用的最少CPU内核数。
它的取值范围在1到最大CPU数量，在UNIX/Linux环境下的默认值是1，在Windows环境下的默认值是最大CPU数量减1。
设置CPU_MIN_COUNT的正确方法首先应该查看当前操作系统可以使用的最大物理CPU数量，以确定CPU_MIN_COUNT最大值，如果物理CPU数量不小于2个，应该将CPU_MIN_COUNT设置为物理CPU数量减1，以确保OS可以获得比Oracle至少一个CPU供其他服务使用，避免Oracle与OS相互干扰；如果物理CPU数量只有1个，那么将CPU_MIN_COUNT设置为1即可。
官方英文解释
CPU_MIN_COUNT specifies the minimum number of CPUs required by a pluggable database (PDB) at any given time.
| Property | Description |
|---|---|
|
Parameter type |
String |
|
Syntax |
|
|
Default value |
The value of |
|
Modifiable |
|
|
Modifiable in a PDB |
Yes |
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Range of Values |
Decimal values from Integer values from |
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Basic |
No |
|
Oracle RAC |
The same value should be used on all instances. |
This parameter specifies the minimum number of CPUs required by a PDB at any given time. For multi-threaded CPUs, this number corresponds to CPU threads, not CPU cores.
You can set this parameter at the CDB level, and for each individual PDB. This enables you to control each PDBs minimum share of CPU utilization within a CDB. If the sum of the CPU_MIN_COUNT values across all open PDBs in a CDB is equal to the value of CPU_MIN_COUNT for the CDB, then the CDB instance is considered full. If the sum exceeds the value of CPU_MIN_COUNT for the CDB, then the CDB instance is over-provisioned. Oracle does not prevent you from over-provisioning a CDB.
Resource Manager is enabled at the CDB level by setting the RESOURCE_MANAGER_PLAN at the root level to the name of a CDB resource plan. If the CDB resource plan has no configured CPU directives, that is, the SHARES and UTILIZATION_LIMIT directives are unset, then Resource Manager uses the CPU_COUNT and CPU_MIN_COUNT settings for the PDB to manage CPU utilization.
Note:
Setting this parameter to a very low value can result in insufficient CPU allocation and poor performance.
See Also:
“CPU_COUNT”
