Thanks Dwain.C

Kindly ignore my earlier post, I missed it completely. Actually, Other four solutions are giving accurate results

My results goes as below:

1.hunchback

WITH C1 AS (SELECT Shift FROM test12 WHERE Rate = 4)

SELECT A.Rate FROM test12 AS A INNER JOIN C1 AS B ON A.Shift = B.Shift

GROUP BY A.Rate HAVING COUNT(*) = (SELECT COUNT(*) FROM C1);

Table 'test12'. Scan count 2, logical reads 48

Query Cost relative to batch = 21%

2.dwain.c

SELECT Rate FROM test12

WHERE Shift IN (SELECT Shift FROM test12 WHERE Rate = 4)

GROUP BY Rate HAVING COUNT(*) = (SELECT COUNT(*) FROM test12 WHERE Rate = 4);

Table 'test12'. Scan count 2, logical reads 48

Query Cost relative to batch = 21%

3.dwain.c (divide and concur)

SELECT Shift INTO #T FROM @T WHERE Rate = @Rate;

DECLARE @Rows INT = @@ROWCOUNT;

SELECT Rate FROM @T

WHERE Shift IN (SELECT Shift FROM #T)

GROUP BY Rate HAVING COUNT(*) = @Rows;

GO

DROP TABLE #T;

Table 'test12'. Scan count 1, logical reads 2

'#T_____00000000000D'. Scan count 1, logical reads 22

Table 'test12'. Scan count 1, logical reads 2

Query Cost relative to batch = 23%

4.dwain.c

WITH Target AS

(SELECT Rate, Shift FROM test12 WHERE Rate = 4)

SELECT c.Rate

FROM

(SELECT Rate, rc=COUNT(*) FROM test12 GROUP BY Rate) a

JOIN

(SELECT rc=COUNT(*) FROM Target) b ON b.rc <= a.rc

JOIN test12 AS c ON c.Rate = a.Rate

JOIN Target AS d ON d.Shift = c.Shift

GROUP BY c.Rate

HAVING COUNT(*) = MIN(b.rc);

Table 'test12'. Scan count 8, logical reads 54,

Query Cost relative to batch = 35%

So, Cost wise, 1 and 2 are performing better then 3.

ElapsedMS is as below:

990

956

960 (Divide and Conquer)

2723

I could not get "Divide and Conquer" at first place.

Thanks again everyone for putting your efforts.