发布网友 发布时间:2022-04-08 09:41
共1个回答
热心网友 时间:2022-04-08 11:10
查找bad sql的方法:select * from (select buffer_gets, sql_text from v$sqlarea where buffer_gets >500000 order by buffer_gets desc) where rownum<=10;执行次数多的SQL:select sql_text,executions from (select sql_text,executions from v$sqlarea order by executions desc) where rownum<10; 读硬盘多的SQL:select sql_text,disk_reads from (select sql_text,disk_reads from v$sqlarea order by disk_reads desc) where rownum<10; 排序多的SQL:select sql_text,sorts from (select sql_text,sorts from v$sqlarea order by sorts desc) where rownum<10; 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:set pagesize 600; set linesize 1000; select substr(sql_text,1,80) "sql", count(*), sum(executions) "totexecs" from v$sqlarea where executions < 5 group by substr(sql_text,1,80) having count(*) > 30 order by 2;游标的观察:set pages 100; select sum(a.value), b.name from v$sesstat a, v$statname b where a.statistic# = b.statistic# and b.name = 'opened cursors current' group by b.name; select count(0) from v$open_cursor; select user_name,sql_text,count(0) from v$open_cursor group by user_name,sql_text having count(0)>40; 查看当前用户&username执行的SQL:select sql_text from v$sqltext_with_newlines where (hash_value,address) in (select sql_hash_value,sql_address from v$session where username='&username') order by address,piece;