[iops] - always "subclass" SELECT

Change-Id: Icb0aed0d2280f7a339a165bbd65b05ed448f8d1f
Reviewed-on: http://review.couchbase.org/28363
Reviewed-by: Mark Nunberg <mnunberg@haskalah.org>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>