摘要： 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(*) "Tot"from v$session_Waitgroup by event order by 4;2. 回滚段的争用情况select name, waits, gets, waits/gets "Ratio"from v$rollstat a, v$rollname bwhere a.usn = b.usn; 阅读全文