找到Oracle数据库中性能最差的查询语句

select b.username username, a.disk_reads reads,a.executions exec, a.disk_reads /decode (a.executions, 0, 1,a.executions) rds_exec_ratio, a.sql_text Statement from V$sqlarea a, dba_users b where a.parsing_user_id = b.user_id and a.disk_reads > 100000 order by a.disk_reads desc

参考
http://www.dedecms.com/knowledge/data-base/oracle/2012/0820/9173.html