V$PX_INSTANCE_GROUP

V$PX_INSTANCE_GROUP provides information about the instance groups being used for parallel operations by the current session.

Column	Datatype	Description
`QC_INSTANCE_GROUP`	`VARCHAR2(64)`	The instance group being used by this session for parallel operations. This value repeats for every row returned.
`WHY`	`VARCHAR2(23)`	Where the current instance group name comes from, as follows: SERVICE - the instance group being used is from the session's service name PARALLEL_INSTANCE_GROUP - the instance group being used is being used because the PARALLEL_INSTANCE_GROUP initialization parameter has been set. The value repeats for every row returned.
`INSTANCE_NUMBER`	`NUMBER`	Instance number of the instance providing this instance group. There will be one row for each instance in the instance group that the Query Coordinator is using.
`CON_ID`	`NUMBER`	The ID of the container to which the data pertains. Possible values include: `0`: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs. `1`: This value is used for rows containing data that pertain to only the root n: Where n is the applicable container ID for the rows containing data