Your question is SQL Join With Partitioning. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Suppose you are managing a student database with a student information table and a test scores table, both keyed by student_id: how would you obtain all student information for students whose average test score is over 90%? Also, what is the time complexity of your approach if the tables are not partitioned, and how does the retrieval process change if the tables are partitioned?