DBTIME

Amount of elapsed time (in microseconds) spent performing Database user-level calls. This does not include the elapsed time spent on instance background processes such as PMON.

elapsed = (busy time + idle time) / cpu_count

cpu*0.1>DB Time/Elapsed，数据库当前时段负载极低

这句话的意思是用户级别的sql执行时间不到数据库cpu时间的 10% 说明cpu不繁忙

你的awr报告取的时间跨度太大，指标被平均了，可以取业务忙时进行分析