Sql IN clause slows down performance

Question

I need a help about sql query performance...

I have a view and when I run view as

select * 
from udv_salesAnalyze 
where _month=12 and _year=2012 

I got result in 2 seconds

but when I add another filter as

select * from udv_salesAnalyze 
where _month=12 and _year=2012 
and userRef in (1,2,5,6,9,11,12,13,14
,19,22,25,26,27,31,34,35,37,38,39,41,47,48,49,53,54,57,59,61,62
,65,66,67,68,69,70,74,77,78,79,80,83,86,87,88,90,91,92,94)  

I got result in 1 min 38 seconds..

I modified query as

select * from udv_salesAnalyze 
where _month=12 and _year=2012 
and userRef in (select * from udf_dependedUsers(2)) 

(here udf_dependedUsers is table returned Function) I got result in 38 seconds

I joined table retuned function to view but again I got result in 38-40 seconds...

is there any other way to get result more fastly...

I ll be very appreciated you can give me a solution...

thanks a lot ...

here code fo udf_dependedUsers :

ALTER FUNCTION [dbo].[udfn_dependedUsers] (@userId int)
RETURNS @dependedUsers table (userRef int)
AS
BEGIN
DECLARE @ID INT
SET @ID = @userId
;WITH ret AS(SELECT userId FROM users
             WHERE  userId = @ID
             UNION ALL
             SELECT t.userId
             FROM   users t INNER JOIN ret r ON t.Manager = r.userId
             ) 
insert into @dependedUsers (userRef)
select * from ret
order by userId
RETURN 
END

Answer 1

Problem was indicies of table which holds user data

Here is Solution ;

1- write your query to Query Editor and Click "Display Estimated Execution Plan" button ..

2- SQL Server gives you hints and query about index in "Execution Plan Window" that should be created on table

3- Right Click on Execution Plan window and choose "Missing Index Details"

4- In Opend Query Page Rename index name ([] to something else which you want) and run query

5- and Run you own query which was slow as I mentiond in my question... after these steps my query run in 4 second instead of 38

Answer 2

Try using a left join

select * from udv_salasAnalyze  MainTable
LEFT JOIN
(select * from udf_dependedUsers(2)) SelectiveInTable --Try direct query like that you wrote in user function
ON SelectiveInTable.userRef = MainTable.userRef
where _month=12 and _year=2012 
and SelectiveInTable.userRef != null

Answer 3

Use a JOIN instead of an IN, like this:

select 
   data.* 
from udv_salesAnalyze data
join ( values
    (1), (2), (5), (6), (9),(11),(12),(13),(14),(19)
   ,(22),(25),(26),(27),(31),(34),(35),(37),(38),(39)
   ,(41),(47),(48),(49),(53),(54),(57),(59)
   ,(61),(62),(65),(66),(67),(68),(69),(70),(74),(77),(78),(79)
   ,(80),(83),(86),(87),(88),(90),(91),(92),(94)
) V(userRef) on V.userRef = data.userRef
where _month = 12
  and _year  = 2012