That's because a trigger does not fire per row, but per query.  If you UPDATE multiple rows, the trigger only fires once, and gives you both the inserted and deleted...

Indexing of the usual kind may not help a lot, unless you limit the search capability to always involve characters at the beginning of the string.   If that were the...

Maybe this:
SELECT
   MAX(CASE WHEN processthreadtype = 'SLOW' THEN ProcessLimit ELSE NULL END) AS [@Slow]
   ,MAX(CASE WHEN processthreadtype = 'EXPRESS' THEN ProcessLimit ELSE NULL END) AS...

Have you looked at using the FORMAT function in SQL Server?   This might be able to avoid the necessity of having to let CSS convert numeric values to strings, and...

A couple of things.   CHAR(10) is the "new line character", or "LINE FEED" (aka LF) from the old days of teletypes.  There was also usually CHAR(13) preceding it, which is...

Not sure this is ever going to go very fast.   Also, using the function that way, while it is an inline table-valued function, the problem is that it's used in...