如题,现有一个表A (recordtime date,
                    hostname varchar2(20),
                    指标a    number);A中的记录是每分钟一条的,如:
2011-11-19 12:01:02   WAP01     3
2011-11-19 12:02:02   WAP01     2
2011-11-19 12:03:02   WAP01     1
2011-11-19 12:04:02   WAP01     3
2011-11-19 12:05:02   WAP01     2
2011-11-19 12:06:02   WAP01     1
2011-11-19 12:07:02   WAP01     3
2011-11-19 12:08:02   WAP01     2
2011-11-19 12:09:02   WAP01     1
2011-11-19 12:10:02   WAP01     3
2011-11-19 12:11:02   WAP01     2
2011-11-19 12:12:02   WAP01     1
现要求,将这些记录每五分钟间隔汇总成一条记录,期望:
2011-11-19 12:05:00   WAP01     11
2011-11-19 12:10:00   WAP01     10
2011-11-19 12:15:00   WAP01     sum(11分-15分的指标a)
求助SQL或什么方法