ORACLE 数据库相关

oracle 识别’低效执行’的SQL语句

用下列SQL工具找出低效SQL：

SELECT 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

ORDER BY 4 DESC;