Temp Table For Repeatedly Used Sub Query

Hi,

Here is my query which lists all orders for products supplied by Supplier-3.
A typical Query on the Northwind database i wrote is like this..

Select * FROM [Order Details] WHERE ProductID in
(Select ProductID From Products where SupplierID = 3)

The subquery in Red was used in multiple places in one of my Stored Procedures..

So what i thought was - use a temp table to store the resultset from this subquery, and then use the temp table instead of querying the Products table everywhere..

My Query looked something like this..

Declare @ProductIDs TABLE
(ProductID int)

INSERT INTO @ProductIDs
Select ProductID From Products where SupplierID = 3

Select * FROM [Order Details] WHERE ProductID in
(Select ProductID FROM @ProductIDs)



Well, I expected an increase in performance with the latter approach, but seems my Stored Procedure is taking more time with the second solution..

Would be glad to see ne explanation on this behavior..

Thanks in Advance..