有时候执行的oracle，sql语句要查看下性能情况，可以用这个进行下简单计算和统计

--http://www.cnblogs.com/Invokerr/p/7084786.html SELECT ELAPSED_TIME,LAST_ACTIVE_TIME,EXECUTIONS,disK_READS,BUFFER_GETS,ROUND((BUFFER_GETS-disK_READS)/BUFFER_GETS,2) Hit_radio,ROUND(disK_READS/EXECUTIONS,2) Reads_per_run,sql_TEXT FROM V$sqlAREA WHERE EXECUTIONS>0 AND BUFFER_GETS > 0 AND (BUFFER_GETS-disK_READS)/BUFFER_GETS < 0.8 and sql_TEXT like '%htjs%' ORDER BY 5 DESC;