I would also like to know why you are getting downvoted.
Even wikipedia uses a Venn diagram to explain JOIN https://en.wikipedia.org/wiki/Join_(SQL) .
Not trying to use an argument from authority but just pointing out that this is not unheard of.
Even wikipedia uses a Venn diagram to explain JOIN https://en.wikipedia.org/wiki/Join_(SQL) .
Not trying to use an argument from authority but just pointing out that this is not unheard of.
People can form different mental models of the same abstraction so I see what you are saying
I've never seen it that way because "Venn diagrams do not generally contain information on the relative or absolute sizes (cardinality) of sets." (see https://en.wikipedia.org/wiki/Venn_diagram).