Multi-statement vs. In line Table Valued Function performance SQL server

Query tuning best practices recommendation  

There are two types of user defined table valued function.

a. Multi-statement table valued function

b. In line table valued function

In general in line table valued function performs better than multi-statement table value function. For example:

CREATE FUNCTION udfInlineGetMostRecentPost (@ntUserID BIGINT)

RETURNS TABLE

AS

RETURN

SELECT TOP (1) *

FROM tblPost

WHERE ntUserID = @ntUserID

ORDER BY dtPostDate DESC

GO

SELECT U.*

     ,P.xlPostData

     ,P.dtPostDate

FROM tblUser U

CROSS APPLY dbo.udfInlineGetMostRecentPost(U.ntUserID) P

   

Execution Time: 8 Seconds

CREATE FUNCTION udfMultiGetMostRecentPost (@ntUserID BIGINT)

RETURNS @tblRecentPost TABLE (

     ntPostID BIGINT

     ,xlPostData XML

     ,dtPostDate DATETIME

     )

AS

BEGIN

     INSERT INTO @tblRecentPost

     SELECT TOP (1) ntPostID

          ,xlPostData

          ,dtPostDate

     FROM tblPost

     WHERE ntUserID = @ntUserID

     ORDER BY dtPostDate DESC

     RETURN

END

GO

SELECT U.*

     ,P.xlPostData

     ,P.dtPostDate

FROM tblUser U

CROSS APPLY dbo.udfMultiGetMostRecentPost(U.ntUserID) P

Execution time: 19 seconds

But it is not possible to write in line table valued function always but if it is possible then we should in line table valued function instead of multi-statement table valued function.