VIEWS with SELECT inside conditions delaying the query - sql-server

Question

In one of my SQL views I am using an inline select statement with a where clause.
The outline of my view is like
ALTER VIEW [dbo].[vw_autumn]
AS
SELECT
BookNumber, Title, shopNo
FROM
(SELECT
BookNumber, Title, shopNO
FROM
(SELECT DISTINCT
(sum_vnr) AS BookNumber,
navn1 AS Title,
tik AS ShopNO,
ROW_NUMBER() OVER (PARTITION BY sum_vnr, tik ORDER BY sum_vnr DESC) AS rownumber
FROM
sum s
INNER JOIN
hod h ON s.tik = h.tik
WHERE
s.aar = (SELECT currentyear
FROM SemesterInfo
WHERE SemName = 'Autumn')
AND CAST(s.sum_vnr AS BIGINT) > 10000
AND (s.id LIKE 'h%' OR s.id LIKE 'H%' OR s.id LIKE 'j%'
OR s.id LIKE 'J%')) a
WHERE rownumber = 1
) b
LEFT JOIN (
------
) p ON b.ShopNO = p.tikk
AND b.ISBN = p.vnr
LEFT JOIN table_k k ON p.aar = k.aar
GO
And if I remove the WHERE clause of
WHERE
s.aar = (SELECT currentyear
FROM SemesterInfo
WHERE SemName = 'Autumn')
and shorten it to
WHERE s.aar =19
I am getting the result of view very quickly. But I am trying to add some dynamic nature to this query and selecting this constant from a settings table
Any thoughts on this? Why is the query taking an indefinite time to load with an inline Where clause?

Answer 1

:try with IN insted of =
WHERE
s.aar in (SELECT currentyear
FROM SemesterInfo
WHERE SemName = 'Autumn')

Answer 2

Rewrite the subquery as a join.
INNER JOIN SemesterInfo si
ON s.aer = si.currentYear
WHERE si.SemName = 'Autumn'
If that doesn't do it, consider keeping this syntax and creating an index on SemName