select b.*
from (select col1
,col2
from yourtable
group by col1
,col2
having count(*)>=2
) as a
inner join yourtable as b
on b.col1=a.col1
and b.col2=a.col2
;
You can can also use COUNT() OVER () to finD duplicates.
e.g.
WITH CTE AS
(
SELECT col1 ,col2 ,col3 , col4
,COUNT(Col1) OVER(PARTITION BY col1, col2) AS DUP_COUNT
FROM TABLE_NAME
)
SELECT *
FROM CTE
WHERE DUP_COUNT > 1