SQL Server Full Text Search Very Slow - sql-server

Question

I have a stored procedure that searches a table which has about 200000+ rows with full text FREETEXT.
Here is the basics of it:
declare #searchKey varchar(150)
if #searchKey Is Null OR LEN(#searchKey)=0
Set #searchKey='""';
Set #searchKey='car';
declare #perPage int
Set #perPage=40
declare #pageNo int
Set #pageNo=1
declare #startIndex int,#endIndex int;
Set #startIndex=#perPage*#pageNo-#perPage+1;
Set #endIndex=#perPage*#pageNo;
Select totalItems
--i pull other colums as well
from (
Select Row_Number() over(order by CreateDate DESC) As rowNumber
,COUNT(*) OVER() as totalItems
--other columns are pulled as well
from MyTable P
Where
#searchKey='""'
OR FreeText((P.Title,P.Description),#searchKey)
) tempData
--where rowNumber>=#startIndex AND rowNumber<=#endIndex
where
rowNumber>=CASE WHEN #startIndex>0 AND #endIndex>0 THEN #startIndex ELSE rowNumber END
AND rowNumber<=CASE WHEN #startIndex>0 AND #endIndex>0 THEN #endIndex ELSE rowNumber END
order by rowNumber
The problem is its running slower then i would like it. Its taking about 3 seconds to load the page. Same page was loading in less then 1 sec when i was using like operator.

Answer 1

In my experience, full text index functions do not work well in a clause that contains an "OR" operator. I have had to get the same behavior by adjusting my query to use a UNION. Try this and see if you can get better performance.
declare #searchKey varchar(150)
if #searchKey Is Null OR LEN(#searchKey)=0
Set #searchKey='""';
Set #searchKey='car';
declare #perPage int
Set #perPage=40
declare #pageNo int
Set #pageNo=1
declare #startIndex int,#endIndex int;
Set #startIndex=#perPage*#pageNo-#perPage+1;
Set #endIndex=#perPage*#pageNo;
Select totalItems
--i pull other colums as well
from (
Select Row_Number() over(order by CreateDate DESC) As rowNumber
,COUNT(*) OVER() as totalItems
--other columns are pulled as well
from
(
select * from
MyTable A
Where
#searchKey='""'
UNION
select * from MyTable B
where FreeText((B.Title,B.Description),#searchKey)
) as innerTable
) tempData
--where rowNumber>=#startIndex AND rowNumber<=#endIndex
where
rowNumber>=CASE WHEN #startIndex>0 AND #endIndex>0 THEN #startIndex ELSE rowNumber END
AND rowNumber<=CASE WHEN #startIndex>0 AND #endIndex>0 THEN #endIndex ELSE rowNumber END
order by rowNumber