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

Domain

SQL

Difficulty

hard

Seniority

L5

Problem

The SRE dashboard needs a quarter-over-quarter view of API latency from Q1 2023 through Q4 2025. For each quarter, show the average latency, the previous quarter's average, and the difference between them. If a quarter has no data, assume an average latency of 120.0.

Summary

Latency trending up or down? The quarters have the answer.

Practice This Problem

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