From: <[EMAIL PROTECTED]> > "Martijn Tonies" <[EMAIL PROTECTED]> wrote on 16/03/2006 11:02:32: > > > Well, the question still is if you should store "unknown" at all ;) > > > > Not according to Date: you should store what is known. See the remarks > > about the "true propositions", from which relational databases are > derived > > (but you probably know that). > > As someone totally unread in the theory of databases, that seems unduly > puritanical. I assume that what Date would propose is that you have > another table (related by master key) in which, if you do not know > something, you do not enter it. But this means that if you have 10 > different pieces of potentially but not necessarily available information > about a single master record (e.g. a person), you have to do a 10-way join > in order to retrieve all the information about them. Replacing a > theoretically ugly null flag with a 10 way join strikes me, as an engineer > rather than a theoretician, the wrong side of the elegance/practicality > trade-off.
Using NULLs as well as de-normalization brings the risk of integrity problems to your storage, storing what is right is only a good thing. And when it comes to having to writing JOINs for all your queries, lo and behold, I bring you the wonder of the VIEW. ;-) Martijn Tonies Upscene Productions http://www.upscene.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
