On 10/18/06, Jim C. Nasby <jim@xxxxxxxxx> wrote:
On Tue, Oct 17, 2006 at 12:51:19PM -0400, Merlin Moncure wrote: > so, imo alexander is correct: > contacto varchar(255) > > ...is a false constraint, why exactly 255? is that were the dart landed? BTW, if we get variable-length varlena headers at some point, then setting certain limits might make sense to keep performance more consistent.
I would argue that it is assumptions about the underlying architecture that got everyone into trouble in the first place :). I would prefer to treat length constraint as a constraint (n + 1 = error), unless there was a *compelling* reason to do otherwise, which currently there isn't (or hasn't been since we got toast) a lot of this stuff s due to legacy thinking, a lot of dbf products had limts to varchar around 255 or so. imo, a proper constraint system would apply everything at the domain level, and minlength and maxlength would get equal weight, and be optional for all types. merlin
