RE: null or not null

You could also point to Codd's Relational Model, which explains that the purpose of a null field is represent the absence of data, because it is either unknown or unecessary. Replacing null with default values, would presume the presence of data that is valid, thus ruining the model of the databases as it was created orginally. Hope this helps. Tony Habib Software Developer, Zentropy Interactive thabib@zentropy.com thabib@cs.sci.csupomona.edu thabib@netroplex.com "Nothing travels faster than the speed of light, except for bad news which obeys its own special laws." -- Douglas Adams, "Mostly Harmless" On Fri, 25 Apr 1997, Scott Black wrote: } Well... First of all why don't you want to? I guess it could be a pain in the !@$ } Tell them that all of the code is written to support nulls and that if they are gone then the code will have all of these useless where clauses... (no wait don't tell them that they might just make you change the code) } Maybe go with a more theoretical approach } Tell them that Informix designed nulls on purpose. They represent the 'unknown' and that if you fill them with default values this defeats the symbolism of a null entry. } I can tell you that in my particular environment there are fields where null is more significant than a default value would be. There are Y/N fields that CANNOT be populated with a default. Maybe you should try to find a specific example like this in your database. } } -----Original Message----- } From: informix-list-owner@rmy.emory.edu [SMTP:informix-list-owner@rmy.emory.edu] On Behalf Of volverine } Sent: Thursday, April 24, 1997 8:11 PM } To: informix-list@rmy.emory.edu } Subject: null or not null } } Ok guys, I need your help on this. } I recently had a "fight" with my supervisors ( who never worked as DBA ) } for "null" and "not null". } According to them, they want to change all the "null" columns in } database to "not null" columns and put a "default" on them. } All they want me to prove is, why can't they do it ?? } Space is not a problem here. But will the performance will get } affected by this ? I really need to have some points to fight them } and surprisingly I am running out of them. Please help !!! } Thanx in advance. }