Transaction strategies: Understanding transaction pitfalls [http://www.ibm.com/developerworks/java/library/j-ts1.html?ca=dgr-jw22SafeJavaTrans&S_TACT=105AGX59&S_CMP=grsitejw22] @Transactional(readOnly = true, propagation=Propagation.REQUIRED) public long insertTrade(TradeData trade) throws Exception { // 어떤 코드 } 위 코드에 있는 insertTrade를 실행행하면 어떤 결과가 발생할까요? A. read-only connection 예외가 발생한다.