Minimum Parallel Workers
A hard SQL mock interview question on DataDriven, with an AI interviewer who asks follow-up questions and a hire or no-hire decision at the end.
- Domain
- SQL
- Difficulty
- hard
- Seniority
- L5
Interview Prompt
We run batch jobs on a shared pool of workers, where a job occupies one worker from its start timestamp until its end timestamp. Find the smallest pool that could have run every completed job without any job ever waiting.
Summary
Too few workers and it stalls.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write and run your SQL against a real database
- Answer the interviewer's follow-up questions, then get a hire or no-hire decision