ORACLE TOP SQL 了解一下

1. 识别’低效执行’的SQL语句

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;

mark一下