2.179 IORM_LIMIT_POLICY
IORM_LIMIT_POLICY
specifies the policy for computing the Exadata I/O Resource Management (IORM) share and limit values for pluggable databases.
Property | Description |
---|---|
Parameter type |
String |
Syntax |
|
Default value |
|
Modifiable |
|
Modifiable in a PDB |
No |
Basic |
No |
Oracle RAC |
Multiple instances should use the same value. |
Values:
-
RM_PLAN
-
If a CDB resource plan is not specified by the user, that is, the CDB resource plan is set to
DEFAULT_CDB_PLAN
, then this setting gives equal IORM shares to all PDBs and specifies no utilization limits. If theCPU_MIN_COUNT
initialization parameter is set, the IORM share values are determined by using the RAC-wide PDB value ofCPU_MIN_COUNT
. Otherwise, the IORM share values for each PDB are determined using the RAC-wide PDB value ofCPU_COUNT
. -
If a user-defined CDB resource plan has been specified by setting the
RESOURCE_MANAGER_PLAN
initialization parameter, then the IORM share and utilization limit values for the PDBs are obtained from that resource plan.
-
-
CPU_COUNT_RATIO
If the
CPU_MIN_COUNT
initialization parameter is set, the IORM share values are determined by using the RAC-wide PDB value ofCPU_MIN_COUNT
. Otherwise, the IORM share values for each PDB are determined using the RAC-wide PDB value ofCPU_COUNT
. In either case, IORM utilization limit values for each PDB are computed as a ratio of the RAC-wide PDBCPU_COUNT
to the RAC-wide CDBCPU_COUNT
.
The IORM utilization limit applies only to flash devices. It is not applicable for hard disks or XRMEM devices. The utilization limit is used for managing flash IOPS and throughput, and is not used to manage PDB flash cache space usage.
Note:
This parameter allows a third setting, CPU_COUNT_BASED
. However, this setting is not supported.
Note:
This parameter is available starting with Oracle Database 23ai.