oracle 中如何定位重要(消耗资源多)的SQL
作者:互联网
oracle 中如何定位重要(消耗资源多)的SQL
发表于 2011 年 2 月 17 日 由 惜分飞联系:手机/微信(+86 13429648788) QQ(107644445)
作者:惜分飞©版权所有[未经本人同意,不得以任何形式转载,否则有进一步追究法律责任的权利.]
1、查看值得怀疑的SQL
select substr(to_char(s.pct, '99.00' ),2)|| '%' load ,
s.executions executes,
p.sql_text
from ( select address,
disk_reads,
executions,
pct,
rank()over( order by disk_reads desc ) ranking
from ( select address,
disk_reads,
executions,
100*ratio_to_report(disk_reads)over() pct
from sys.v_$sql
where command_type!=47)
where disk_reads>50*executions) s,
sys.v_$sqltext p
where s.ranking<=5
and p.address=s.address
order by 1, s.address, p.piece;
|
2、查看消耗内存多的sql
select b.username,
a. buffer_gets,
a.executions,
a.disk_reads / decode(a.executions, 0, 1, a.executions),
a.sql_text SQL
from v$sqlarea a, dba_users b
where a.parsing_user_id = b.user_id
and a.disk_reads > 10000
order by disk_reads desc ;
|
3、查看逻辑读多的SQL
select *
from ( select buffer_gets, sql_text
from v$sqlarea
where buffer_gets>500000
order by buffer_gets desc )
where rownum<=30;
|
4、查看执行次数多的SQL
select sql_text, executions
from ( select sql_text, executions from v$sqlarea order by executions desc )
where rownum < 81;
|
5、查看读硬盘多的SQL
select sql_text, disk_reads
from ( select sql_text, disk_reads from v$sqlarea order by disk_reads desc )
where rownum<21;
|
6、查看排序多的SQL
select sql_text, sorts
from ( select sql_text, sorts from v$sqlarea order by sorts desc )
where rownum<21;
|
7、分析的次数太多,执行的次数太少,要用绑变量的方法来写sql
select substr(sql_text, 1, 80) "sql" , count (*), sum (executions) "totexecs"
from v$sqlarea
where executions < 5
group by substr(sql_text, 1, 80)
having count (*) > 30
order by 2;
|
标签:text,SQL,消耗,executions,reads,sql,oracle,disk,select 来源: https://www.cnblogs.com/yaoyangding/p/14784576.html