The Crowded Hour

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

Domain

SQL

Difficulty

easy

Seniority

L5

Problem

We run a consumer app and size capacity per device type, so we need each type's busiest moment. Find the session window (from its start to its start plus duration) with the most users active at the same time, and return the device type, that window written as start to end, and the number of users active.

Summary

Every device type has a moment when the room is fullest. Find it.

Practice This Problem

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