Malcolm Tredinnick’s SQL puzzle solution

The puzzle

Malcolm has asked, how to find the classes that were attended by all of the students from a given list. Then, he proposed a solution with a HAVING clause. I’ll call it the one-join solution. I’d like to suggest another one, which I’ll call multi-join.

I’ve made a benchmark to evaluate the execution time. A statistical tool was used to create a mathematical model of the execution time.

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