On Mon, 2006-07-03 at 11:09, Scott Ribe wrote: > > Can't the intelligent practitioner simply proceed carefully with > > queries when nulls are involved? > > Yes. The thing is, getting rid of NULL in the real world requires > decomposing data into so many tables that it would certainly cause more > confusion when it comes time to actually query the data... I would add that sometimes null means we don't know, but we wish we did, and here's how we can describe our lack of knowledge... Those instances are the ones we would need lots of tables to describe, and infinite time would allow us to do so. However, there are often nulls that fall in the category of "who cares?" For those, null is a perfectly acceptable alternative, and there's no need for all the extra work.