[菜鸟问题]关于SELECT的问题

[y_h_zhang]

有一如下表:
COL1 COL2
001 ZZZ
002 XXX
003 YYY
003 IDE
004 JUD
. .
. .
. .
想找出COL1中所有重复数据的记录,怎么做(数据量很大)?

[leborety]

select col1 from tab a group by col1 having count(col1)>1

[dinya2003]

select * from
(
select a.*,row_number() over(partition by a.col1 order by a.col2) rank from testa a
) where rank>1