11g中引入一些功能强大的hint提示，其中就包括了IGNORE_ROW_ON_DUPKEY_INDEX。其官方定义为: "The IGNORE_ROW_ON_DUPKEY_INDEX hint applies only to single-table INSERT operations. It is not supported for UPDATE, DELETE, MERGE, or multitable insert operations. IGNORE_ROW_ON_DUPKEY_INDEX