On Fri, Jun 09, 2006 at 05:20:46PM +0200, Martijn van Oosterhout wrote: > On Fri, Jun 09, 2006 at 07:09:12AM -0400, Agent M wrote: > > Well, the Date argument against NULLs (and he never endorsed them, > > or so he claims) is that they are not data- they represent the > > absence of data- so why put non-data in a _data_base. > > At this point you could start a whole philosophical discussion about > whether knowing you don't know something is a fact worth storing. And to me, the answer is an unqualified "yes." A state of ignorance is an important piece of information by itself. For example, that I don't know someone's birthdate is important. When I'm trying to figure out when to send a birthday card, knowing that I don't know this piece of information means that I take a different action "decide whether to try to find out what the birthdate is." from the action I would take if I didn't know that I don't know the birthdate, which is "rummage through all my records trying to find the birthdate." Cheers, D -- David Fetter <david@xxxxxxxxxx> http://fetter.org/ phone: +1 415 235 3778 AIM: dfetter666 Skype: davidfetter Remember to vote!