oracle 中如何定位重要(消耗资源多)的SQL

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　　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.rankingand 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　　4、查看执行次数多的SQL
select sql_text, executions from (select sql_text, executions from v$sqlarea order by executions desc) where rownum 　　5、查看读硬盘多的SQL
select sql_text, disk_reads from(select sql_text, disk_reads from v$sqlarea order by disk_reads desc) where rownum　　6、查看排序多的SQL
select sql_text, sorts from(select sql_text, sorts from v$sqlarea order by sorts desc) where rownum　　7、分析的次数太多，执行的次数太少，要用绑变量的方法来写sql
select substr(sql_text, 1, 80) "sql", count(*), sum(executions) "totexecs"from v$sqlarea where executions group by substr(sql_text, 1, 80) having count(*) > 30 order by 2;