取决于你字段定义的是 timestamp(3)还是timestamp(6)
INSERT INTO TEST VALUES(to_timestamp('2013-9-16 17:03:00.29999', 'yyyy-mm-dd hh24:mi:ss:ff'),to_timestamp('2013-9-16 17:03:00.29999', 'yyyy-mm-dd hh24:mi:ss:ff'));
下面是结果
2013-9-16 17:03:00.300 2013-9-16 17:03:00.299990
timestamp(3)字段会将数据进行四舍五入