Nice. I didn't see your test data and haven't had a chance to roll my own yet. I am guessing that the big difference is that my code uses STUFF and yours does not.

If you still have your test harness handy try with this.

ALTER FUNCTION [dbo].[StripNonNumeric_itvf](@OriginalText VARCHAR(8000))

RETURNS TABLE WITH SCHEMABINDING AS

return

WITH

E1(N) AS (select 1 from (values (1),(1),(1),(1),(1),(1),(1),(1),(1),(1))dt(n)),

E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows

E4(N) AS (SELECT 1 FROM E2 a, E2 b), --10E+4 or 10,000 rows max

Tally(N) AS

(

SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4

)

, clean_text(CleanedText) as

(

SELECT SUBSTRING(@OriginalText, t.N, 1)

FROM tally t

WHERE ASCII(SUBSTRING(@OriginalText, t.N, 1)) BETWEEN 48 AND 57

FOR XML PATH('')

)

select CleanedText

from clean_text