数据库名称： PostgreSQL
数据库版本： 9.3.6
内容/问题描述：
现在有好几笔资料 data_timestamp data_name VALUE
"2015-10-28 13:49:43.191" "CPU UTIL" "13"
"2015-10-28 13:54:43.261" "CPU UTIL" "31"
"2015-10-28 13:59:43.066" "CPU UTIL" "18"
"2015-10-28 14:04:43.047" "CPU UTIL" "06"
"2015-10-28 14:09:43.233" "CPU UTIL" "12"
"2015-10-28 14:14:42.947" "CPU UTIL" "07"
"2015-10-28 14:19:43.034" "CPU UTIL" "15"
"2015-10-28 14:24:42.996" "CPU UTIL" "07"
"2015-10-28 14:29:42.962" "CPU UTIL" "03"
"2015-10-28 14:34:43.017" "CPU UTIL" "03"
"2015-10-28 14:39:42.978" "CPU UTIL" "04"
"2015-10-28 14:44:42.897" "CPU UTIL" "03"
"2015-10-28 14:49:42.907" "CPU UTIL" "01"
我想把资料用弄成 data_timestamp data_name avg
"2015-10-28 13:00:00.000" "CPU UTIL" "20.6"
"2015-10-28 14:00:00.000" "CPU UTIL" "6.1"
想要把资料时间用成每1小时，value的部分是该区间的平均值
不晓得有没有办法可以达到这个目的
各位不好意思
每小时已经透过将时间截断的方式做出来了
现在想要改成将时间每五分钟的资料合并
也就是把每小时改成每五分钟，目前没有想到要怎么把10 11 12分钟通通变成10的方式.