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	IORM_LIMIT_POLICY = { RM_PLAN | CPU_COUNT_RATIO }
Default value	RM_PLAN
Modifiable	ALTER SYSTEM
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 the CPU_MIN_COUNT initialization parameter is set, the IORM share values are determined by using the RAC-wide PDB value of CPU_MIN_COUNT. Otherwise, the IORM share values for each PDB are determined using the RAC-wide PDB value of CPU_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 of CPU_MIN_COUNT. Otherwise, the IORM share values for each PDB are determined using the RAC-wide PDB value of CPU_COUNT. In either case, IORM utilization limit values for each PDB are computed as a ratio of the RAC-wide PDB CPU_COUNT to the RAC-wide CDB CPU_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 AI Database 26ai.