A hard SQL interview practice problem on DataDriven. Write and execute real sql code with instant grading.

Domain

SQL

Difficulty

hard

Seniority

L5

Problem

Determine the minimum number of parallel workers required to run all batch jobs without conflicts. Each job has a start and end timestamp and can overlap with others. Duplicate job entries should be counted once, and jobs missing start or end times should be excluded. Find the peak number of concurrently running jobs at any point.

Summary

Too few workers and it stalls.

Practice This Problem

Solve this SQL problem with real code execution. DataDriven runs your SQL queries against a real database and grades it automatically.