监控 SQL 1.监控事例的等待： select event,sum(decode(wait_time,0,0,1)) prev, sum(decode(wait_time,0,1,0)) curr,count(*) from v$session_wait group by event order by 4; 2.回滚段的争用情况： select name,waits,gets,waits/gets ratio from v$rollstat a,v$rollname b where a.us
ASIC（专用集成电路） Application-Specific Integrated Circuit. A piece of custom-designed hardware in a chip. 专用集成电路。一个在一个芯片上定制设计的硬件。 address bus （地址总线） A set of electrical lines connected to the processor and all of the peripherals withwhich itcommunicates.
