As always thanks for bringing something extra to the table. We always think and answer questions is the scope of our own experience ( and knowledge ) and I'm really glad this question was asked and to see your answer. While I'm confident mine works in the scope i deal with, I have just learned a lot about a question I didn't know was a question <g> and will be watchful of *ass*uming my world is *the* world <g>

Now I have to go read a bunch of stuff I didn't know existed <s> You really know how to screw up my weekend.

I'd rather bring beer to the table. <s>

Working in this industry is much like being a doctor/surgeon (except we don't get paid quite as well). A person has to be reading almost constantly, to keep up with what's outside.

I'm fortunate in that I have hundreds of students who graduate and then email me back and tell me how they're using the technology in small-medium-large companies. Sometimes they recognize patterns I previously told them about, and sometimes they tell me about approaches being used that I've never heard of (and then MY weekend gets blown researching what they're talking about).

Now, on the original question, I am sure that many people have used zeros or nulls instead of an "unassigned" member/row, and the sky didn't fall. This industry is rarely an exact science. But there's a single magic word in the business application area....the magic word "by". Users (and execs) want to see data "by this", "by that", "by every possible combination". And so the more a database is built to support that, the happier everybody is.