Where ‘possible table contents’ is the cross product given A and B.
Cross product gives us everything outside the diagram as well as what is inside. …Within the scope of possible results that is. This is all in a bigger circle. As far as I can see, the model holds. And if it doesn’t? Then we just need another circle to contain the instances where it fails. 
@codinghorror your work has been replicated in es6 
BTW, I can’t count the number of times I’ve referred back to this page over the years. Thanks.
Good post, very clear!
Note: the image for inner join is returning 404.
It’s a Ghost Pro hosting issue… their CDN isn’t returning the image. I’ve written them about it.
Helped me a LOT !!
Thank you for sharing 
I think this has been in my bookmarks for about 6-7 years now and it’s where I go everytime I need my memory jogged
Welcome to the community, Ewan! Everyone’s memory needs to be jogged every once in a while. That’s why I’ve been reading the old topics for some time. I even get a few good laughs from some of the remarks. Refreshing in more than one way. 