1  --查找bad sql的方法: 
 2 
 3   select * from (select buffer_gets, sql_text 
 4 
 5   from v$sqlarea 
 6 
 7   where buffer_gets >500000 
 8 
 9   order by buffer_gets desc) where rownum<=30; 
10 
11  -- 执行次数多的SQL 
12 
13   select sql_text,executions from 
14 
15   (select sql_text,executions from v$sqlarea order by executions desc) 
16 
17   where rownum<81; 
18 
19  -- 读硬盘多的SQL 
20 
21   select sql_text,disk_reads from 
22 
23   (select sql_text,disk_reads from v$sqlarea order by disk_reads desc) 
24 
25   where rownum<21; 
26 
27  -- 排序多的SQL 
28 
29   select sql_text,sorts from 
30 
31   (select sql_text,sorts from v$sqlarea order by sorts desc) 
32 
33   where rownum<21;