I've noticed MetamodelImpl.getImplementors method is invoked whenever a criteria is executed with list() , getImplentors is iterating over all entity persisters available (>600 in my model) to resolve the implementors for a given class name, finally this causes a considerable overhead.

Given the implementors for a concrete class name would always be the same. It would be convenient to cache it.

Discussed in forums: https://forum.hibernate.org/viewtopic.php?f=1&t=1044025