Cadavre (12/6/2011)
I assumed that understanding the logic of join operators is integral to the majority of the visitors to this site.
Not, I believe, a safe assumption. In my daily routine as an "Accidental DBA", I write relatively few queries, and very, very few complex queries with joins. I visit the site to learn, so that I have a chance of writing the queries quickly and efficiently when needs arise. (Of course, something is apparently rubbing off, 'cause I apparently got today's question right AND learned something!)