--查询当前执行IO最多的sql，并按大到小来排序
select cast(buffer_gets/decode(EXECUTions,0,10000,EXECUTions) as int) 平均IO ,
EXECUTions 执行次数,buffer_gets 总逻辑IO,disk_reads 硬盘读取,
sql_text SQl语句 from v$sqlarea
where parsing_schema_name='HQT'
order by buffer_gets desc