Where the Lights Stay On

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

Domain

SQL

Difficulty

medium

Seniority

L4

Problem

An SRE team is compiling a reliability leaderboard by region, where a probe's effective hours is its uptime minus a tenth of its latency, and a probe with no recorded latency counts as having zero latency. Total each region's effective hours and surface the three most reliable regions, with equal totals sharing a place.

Summary

The most reliable regions.

Practice This Problem

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