Sensible Hibernate batch properties

  <property name="hibernate.jdbc.batch_size" value="30"/>
  <property name="hibernate.order_inserts" value="true"/>
  <property name="hibernate.order_updates" value="true"/>
  <property name="hibernate.jdbc.batch_versioned_data" value="true"/>

Also for postgresql and hibernate < 5.2 add "?reWriteBatchedInserts=true" to connection url.