SQL Server 2005 - Levenshtein Distance

This function calculates the Levenshtein Distance

If anyone can improve the speed, please post the improved code here.

sql Code:

-- =============================================
-- Author:      <Michael Ciurescu>
-- Create date: <20090707>
-- Description: <See: [url]http://www.merriampark.com/ld.htm[/url] >
-- =============================================
CREATE FUNCTION dbo.fn_LevenshteinDistance
(
      @Str1 VARCHAR(MAX)
    , @Str2 VARCHAR(MAX)
)
RETURNS INT
AS
BEGIN
    /*
        SELECT dbo.fn_LevenshteinDistance('test', 'test')
        SELECT dbo.fn_LevenshteinDistance('tesot', 'test')
        SELECT dbo.fn_LevenshteinDistance('testing1', 'tes_ing')
    */
    
    DECLARE @m INT, @n INT
    DECLARE @editMatrix TABLE(pk1 INT, pk2 INT, v INT, PRIMARY KEY (pk1, pk2))
    DECLARE @i INT, @j INT, @cost INT
    DECLARE @str1_i CHAR, @str2_j CHAR
    
    SET @n = DATALENGTH(ISNULL(@Str1, ''))
    SET @m = DATALENGTH(ISNULL(@Str2, ''))
    
    IF @n = 0 OR @m = 0 RETURN 0
    
    SET @i = 0
    WHILE @i <= @n BEGIN
        SET @j = 0
        WHILE @j <= @m BEGIN
            IF @j = 0
                INSERT INTO @editMatrix VALUES(@i, 0, @i)
            ELSE IF @i = 0
                INSERT INTO @editMatrix VALUES(0, @j, @j)
            ELSE
                INSERT INTO @editMatrix VALUES(@i, @j, 0)
            
            SET @j = @j + 1
        END
        
        SET @i = @i + 1
    END
    
    SET @i = 1
    WHILE @i <= @n BEGIN
        SET @str1_i = SUBSTRING(@Str1, @i, 1)
        
        SET @j = 1
        WHILE @j <= @m BEGIN
            SET @str2_j = SUBSTRING(@Str2, @j, 1)
            
            IF @str1_i = @str2_j
                SET @cost = 0
            ELSE
                SET @cost = 1
            
            UPDATE em
            SET v = (
                        SELECT MIN(ret) AS MIN_ret
                        FROM (
                            SELECT v + 1     AS ret FROM @editMatrix WHERE pk1 = @i - 1 AND pk2 = @j     UNION ALL
                            SELECT v + 1     AS ret FROM @editMatrix WHERE pk1 = @i     AND pk2 = @j - 1 UNION ALL
                            SELECT v + @cost AS ret FROM @editMatrix WHERE pk1 = @i - 1 AND pk2 = @j - 1
                        ) AS x
                    )
            FROM @editMatrix AS em
            WHERE pk1 = @i AND pk2 = @j
            
            SET @j = @j + 1
        END
        
        SET @i = @i + 1
    END
    
    RETURN (SELECT ISNULL(v, -1) FROM @editMatrix WHERE pk1 = @n AND pk2 = @m)
END

I found much faster code over here: http://www.sqlteam.com/forums/topic....40&whichpage=1