Parameter Sniffing Not working - sql

Question

I am using MSSQL. I have a stored procedure which works fine for couple of days and later on it becomes slow. I came to know that Parameter Sniffing will work for it. How ever after implementing it it became slow for ever. I also tried to Recompiling job. I faced the same slowness issue immediately.
Can some one please help me with this ?
Below is the structure of my Stored Procedure.
#START_VALUE int=null,
#END_VALUE int=null
#UID NVARCHAR(MAX)=null,
AS
BEGIN
SELECT
dbo.TABLE1.ID,
ROW_NUMBER() OVER (ORDER BY TABLE1.UPDATED_ON desc) AS RN,
CONVERT(VARCHAR(10), dbo.TABLE1.DATE, 101) AS TDATE,
CATEGORY = (
SELECT TOP 1 COLUMN1
FROM TABLE5 CT1
WHERE TABLE1.CATEGORY = CT1.CATEGORY_ID
),
TYPETEXT = (
SELECT TOP 1 COLUMN1
FROM TABLE6 CT1
WHERE TABLE1.TYPE = CT1.TYPE_ID
),
IMAGE = STUFF(( SELECT DISTINCT ',' + CAST(pm.C1 AS varchar(12))
FROM TABLE2 pm
WHERE pm.ID = TABLE1.ID AND pm.C1 IS NOT NULL AND pm.C1 <> ''
FOR XML PATH('')),
1, 1, '' ) INTO #tempRecords
FROM dbo.TABLE1
WHERE ((#UID is null OR dbo.TABLE1.ID = #UID )
ORDER BY TABLE1.UPDATED DESC
SELECT #count = COUNT(*) FROM #tempRecords;
SELECT *, CONVERT([int],#count) AS 'TOTAL_RECORDS'
FROM #tempRecords
WHERE #tempRecords.RN BETWEEN CONVERT([bigint], #START_VALUE) AND CONVERT([bigint], #END_VALUE)
END
GO

Answer 1

To make the query optimized for parameter sniffing, declare dummy variables and use them in your query, as opposed to using the original parameters as such.
CREATE PROCEDURE test_proc
#START_VALUE INT=NULL,
#END_VALUE INT=NULL,
#UID NVARCHAR(max)=NULL
as
BEGIN
DECLARE #START_VALUE_SNIFF INT=NULL,
#END_VALUE_SNIFF INT=NULL,
#UID_SNIFF NVARCHAR(max)=NULL
SET #START_VALUE_SNIFF = #START_VALUE
SET #END_VALUE_SNIFF = #END_VALUE
SET #UID_SNIFF = #UID
select * from
FROM dbo.TABLE1
WHERE ((#UID_SNIFF is null OR dbo.TABLE1.ID = #UID_SNIFF )
ORDER BY TABLE1.UPDATED DESC
END