INSTANCE_GROUPS

Property	Description
Parameter type	String
Syntax	`INSTANCE_GROUPS =` `group_name` `[,` `group_name` `] ...`
Default value	There is no default value.
Modifiable	No
Range of values	One or more instance group names, separated by commas
Basic	No
Real Application Clusters	Multiple instances can have different values.

INSTANCE_GROUPS is a Real Application Clusters parameter that you can specify only in parallel mode. Used in conjunction with the PARALLEL_INSTANCE_GROUP parameter, it lets you restrict parallel query operations to a limited number of instances.

This parameter specifies one or more instance groups and assigns the current instance to those groups. If one of the specified groups is also specified in the PARALLEL_INSTANCE_GROUP parameter, then Oracle allocates query processes for a parallel operation from this instance.