StringBuilder is a great example. So is pretty much any math operation. Recently, I've been playing with the following method, which mathematically reverses an integer:

-----------------------------------------------------------

[SqlFunction]

public static int ReverseNumber (int number)

{

int reverse = 0;

do

{

reverse = (reverse * 10) + (number % 10);

number = number / 10;

}

while (number > 0);

return (reverse);

}

-----------------------------------------------------------

Here is the equivalent in a T-SQL UDF:

-----------------------------------------------------------

CREATE FUNCTION dbo.NumberReverse

(

@InputNum INT

)

RETURNS INT

AS

BEGIN

DECLARE @Reverse INT

SET @Reverse = @InputNum % 10

SET @InputNum = @InputNum / 10

WHILE @InputNum > 0

BEGIN

SET @Reverse = (@Reverse * 10) + (@InputNum % 10)

SET @InputNum = @InputNum / 10

END

RETURN (@Reverse)

END

GO

-----------------------------------------------------------

Run both of these 10000 or 100000 times on your system, using a script such as the following:

DECLARE @i INT

SET @i = 1

DECLARE @j-2 INT

SET @j-2 = 1234567

WHILE @i < 10000

BEGIN

SET @j-2 = dbo.NumberReverse(@j)

SET @i = @i + 1

END

... On my test system, the CLR version runs twice as fast. I'd be interested in hearing others' results.