Setting such a query hint to TRUE should result in all entities being retrieved by that query to be read-only for the purposes of change-tracking. Note that the entities themselves need not necessarily be read-only in general.

This feature is a flush performance tweak that can be used to query for objects but not let the returned objects run through change-tracking on flush. Any other managed objects are tracked as usual so you can do a read-only query for 100 entities and persist a new entity in the same unit of work with optimal flushing performance.