The Loudest Rooms

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

Domain

SQL

Difficulty

medium

Seniority

L4

Problem

We run a community app where the people who post in chat channels are the same people we serve ads to. For each channel, find how many ad impressions reached the people who post in it, busiest first.

Summary

Every channel has an audience. Find where it is biggest.

Practice This Problem

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