On every row insert Hibernate issues a select statement to fetch database generated values. I am curious about whether or not Hibernate can or does make use of Statement.RETURN_GENERATED_KEYS or similar returning * construct (wherever supported) to do away with issuing an additional query for fetching generated values.
Yes, Hibernate usually relies on the JDBC driver support for this, but whether or not this is relied upon is dependent on the identity support a Hibernate dialect exposes.