SQL優化常用方法22

識别'低效執行'的SQL語句

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;