oracle 中如何定位重要(消耗资源多)的SQL

2021/5/19 19:31:54

编程Tag： select text SQL oracle 消耗 READS DISK executions

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oracle 中如何定位重要(消耗资源多)的SQL

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标题：oracle 中如何定位重要(消耗资源多)的SQL

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;

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oracle 中如何定位重要(消耗资源多)的SQL

oracle 中如何定位重要(消耗资源多)的SQL

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