Welcome to your interview.
The question is on your right: Join vs Union in Analytics. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
Data analysts often need to either combine related datasets or append similar datasets together. Knowing whether to use a JOIN or a UNION is a basic but important SQL decision because the result shape and meaning are very different.
Explain the difference between a JOIN and a UNION in SQL in the context of data analysis.
Your answer should address:
JOINUNION or UNION ALLThe interviewer is looking for a practical explanation, not just syntax definitions. Focus on how these operations change the structure of data, what business questions they answer, and why using the wrong one can lead to incorrect analysis.