Как оптимально разложить строку на составляющие?

DECLARE @s varchar(128)

SET @s=' 3,5, 8,13,21 ,34,55 '

N

---


 3

 5

 8

13

21

34

55

CREATE FUNCTION [dbo].[fnParseIDs] (@IDs varchar(8000))  

RETURNS @res table (id int)

 AS  

BEGIN 

declare @p int

declare @id varchar(10)

declare @c char(1), @asci int

declare @len int

set @len=len(@IDs)

set @p=1

set @id=''

while @p<=@len

begin

	set @c=substring(@IDs,@p,1)

	set @asci=ascii(@c)

	if @asci<48 or @asci>57

	begin

		if not @id=''

		begin

			insert @res values (cast(@id as int))

			set @n=@n+1

			set @id=''

		end

	end

	else

		set @id=@id+@c

	set @p=@p+1

end

if not @id=''

	insert @res values (cast(@id as int))

return

END

CREATE FUNCTION SPLIT (

	@string varchar(8000),

	@delimeter varchar(1) = ',')

RETURNS @ret TABLE (id int PRIMARY KEY)

AS

BEGIN

	DECLARE @s int, @e int



	SET @s = 0

	WHILE CHARINDEX(@delimeter,@string,@s) <> 0

	BEGIN

		SET @e = CHARINDEX(@delimeter,@string,@s)

		INSERT @ret VALUES (CONVERT(int,SUBSTRING(@string,@s,@e - @s)))

		SET @s = @e + 1

	END

	INSERT @ret VALUES (CONVERT(int,SUBSTRING(@string,@s,8000)))

	RETURN

END

DECLARE @s varchar(128)

SET @s=' 3,5, 8,13,21 ,34,55 '

set @s=REPLACE(@s,',',' union all select ')

exec ('select '+@s)