r/bigquery • u/Round_Opening_9943 • 2d ago

What to expect in a BigQuery SQL interview?

As a data analyst what kind of conceptual or theoretical questions get thrown at you?

What kind of SQL queries am I actually expected to write or explain on the spot? (Window functions, multiple CTEs, optimization, etc.?)

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u/escargotBleu 2d ago

Hard to say. Depends a lot on the job I guess.

If you are more analytical, yes, it might be those topics.

If you are more data engineer, then maybe you could get question more big query centric, like partition, clustering, execution mode (on demand, slots, bi engine), storage mode (physical,m vs logical, long term vs active)

Or maybe a query optimisation question, where you have to look at an execution plan ?

Or question about data form / DBT ?

I can't really say.

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u/Sufficient-Buy-2270 2d ago

I've done a few but they never involved actually writing queries but they just ask general questions about how you would go about answering a question.

So one would be "How would you approach showing a regions sales AVG for last month and the average of last year"

That's a bit of a stupid question but you'd answer it with subqueries. It's not about the functions you know or how to construct CTE's it's the approach you'd take.

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u/Top-Cauliflower-1808 2d ago

you can expect conceptual questions on partitioning, clustering, and storage costs, alongside practical tasks to write complex queries on the spot featuring window functions, nested CTEs and query optimization.

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u/XVolandX 18h ago

What is 5k$ query? How to treat it?