In your reply, the implication (emphasized by me above) is that a GUID has a larger capacity than a bigint. The actual number of unique values of a GUID is...

I've been thinking about this issue for a few days. Like everyone, I accept that using a single integer field is going to be the best performance, but I...

Unrelated suggestion or correction:

I noticed you used this statement to remove the procedure before recreating it

if exists(select * from sysobjects where id = object_id('dbo.proc_simple') and type = 'P')

drop procedure dbo.proc_simple

go

I've...