如何定位消耗多的sql语句

select b.username 用户名,a.disk_reads 磁盘读取量,a.executions 执行时间,
a.disk_reads/decode(a.executions,0,1,a.executions) 单位读取数,a.sql_text SQL语句
from v$sqlarea a,dba_users b
where a.parsing_user_id = b.user_id
 and a.disk_reads >10000
order by disk_reads desc;
可以把disk_reads 改成buffer_gets则求出消耗内存多的sql