db2基本语法----分页查询(查前几名)

统计所有报警数量最多的主机前三名，写出查询语句，截图查询结果。 
SELECT CNAME,NUMS FROM(
SELECT
    C.NAMES AS CNAME,SUM(A.NUM) AS NUMS,ROW_NUMBER() OVER (ORDER BY SUM(A.NUM) DESC ) AS AAA
FROM
    LOGSTATUS_DAY1 A 
        JOIN MONITORITEM1 B 
        ON A.MONITORITEMID=B.ID 
            JOIN MONITORINSTANCE1 C 
            ON B.INSTANCEID=C.ID  GROUP BY C.NAMES ORDER BY SUM(A.NUM) DESC)
WHERE AAA<4