查询IO相关SQL

--查询当前执行IO最多的sql，并按大到小来排序

select parsing_schema_name, 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 = 'AML2010' --属主

order by buffer_gets desc;

--查找前十条性能差的sql

select *

from (select parsing_user_id,

executions,

sorts,

command_type,

disk_reads,

sql_text

from v$sqlarea

order by disk_reads desc)

where rownum <= 10;

--查看占io较大的正在运行的session

select se.sid,

se.serial#,

pr.spid,

se.username,

se.status,

se.terminal,

se.program,

se.module,

se.sql_address,

st.event,

st.p1text,

st.p1,

st.p2,

st.p3,

st.state,

st.seconds_in_wait,

si.physical_reads,

si.block_changes

from v$session se, v$session_wait st, v$sess_io si, v$process pr

where st.sid = se.sid

and st.sid = si.sid

and se.paddr = pr.addr

and se.sid > 6

and st.wait_time = 0

and st.event not like '%SQL%'

order by physical_reads desc;

select b.spid,

c.piece,

a.username,

a.machine,

a.program,

a.sid,

a.serial#,

a.status,

c.piece,

c.sql_text,

d.sql_fulltext

from v$session a, v$process b, v$sqltext c, v$sqlarea d

where b.addr = a.paddr

and a.sql_address = c.address(+)

and c.sql_id = d.sql_id

and a.sql_id = d.sql_id

and b.spid = '10438'

order by c.piece

--查询走哪些SQL走了全表扫描

select distinct a.sql_text, a.sql_id, b.options, a.last_load_time, b.operation

from v$sql a, v$sql_plan b

where a.sql_id = b.sql_id

and a.last_load_time like '2015-04-15%'

and b.options = 'FULL'

and b.operation = 'TABLE ACCESS'