<property name="hibernate.use_sql_comments" value="true" />

• http://docs.jboss.org/hibernate/stable/entitymanager/reference/en/html/objectstate.html#d0e1215
• query.setHint(String name, Object value)
• org.hibernate.comment : 쿼리 주석 지정. PersistenceUnit 프라퍼티에 hibernate.use_sql_comments가 true로 지정돼 있을 때 쿼리에 주석으로 출력된다.
• org.hibernate.readOnly : 쿼리의 결과를 Persistence Context에 저장하지 않고, Dirty Check(변경 여부 검사 후 자동 업데이트)도 하지 않게 한다. 성능이 빨라지지만 자동 Update 작동 안함.

• org.hibernate.timeout Query timeout in seconds ( eg. new Integer(10) )
• org.hibernate.fetchSize Number of rows fetched by the JDBC driver per roundtrip ( eg. new Integer(50) )
• org.hibernate.cacheable Whether or not a query is cacheable ( eg. new Boolean(true) ), defaults to false
• org.hibernate.cacheMode Override the cache mode for this query ( eg. CacheMode.REFRESH )
• org.hibernate.cacheRegion Cache region of this query ( eg. new String(“regionName”) )
• org.hibernate.flushMode Flush mode used for this query (useful to pass Hibernate specific flush modes, in particular MANUAL).
• org.hibernate.cacheMode Cache mode used for this query