(Cluster environments only) Returns the instance ID on which the specified process ID (spid) is running.
spid_instance_id(spid_value)
select spid_instance_id(27)
If you do not include a spid value, spid_instance_id returns NULL.
If you enter an invalid or nonexisting process ID value, spid_instance_id returns NULL.
ANSI SQL – Compliance level: Transact-SQL extension.
Any user can execute spid_instance_id.