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; |