App Stability by Region

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

Domain

SQL

Difficulty

medium

Seniority

L5

Problem

The mobile team needs crash rates before the next rollout decision. For each combination of tag and date, count app opens, count crashes, and compute the crash rate as crashes divided by opens, rounded to 4 decimal places. Only consider open and crash events.

Summary

Some regions crash more than others.

Practice This Problem

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