If using Query.setFirstResult(int) with DB2400Dialect an Exception is thrown:
java.lang.UnsupportedOperationException: query result offset is not supported
This problem didn't occur in previous versions (prior to Hibernate version 5).
Working with DB2Dialect Query.setFirstResult(int) works. Looking at the code of DB2Dialect, I assume that DB2400Dialect could use the same LimitHandler as DB2Dialect.