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oracle 中如何定位重要(消耗资源多)的SQL

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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

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标题:oracle 中如何定位重要(消耗资源多)的SQL

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