The Schema That Could Not Answer Back

A hard Data Modeling interview practice problem on DataDriven. Write and execute real data modeling code with instant grading.

Domain

Data Modeling

Difficulty

hard

Seniority

L5

Problem

A personal styling service tracks shipments in a single wide denormalized table with one row per shipment, repeating item attributes across numbered columns. The business wants to add return reasons, calculate client lifetime value, and attribute revenue by brand. The current table cannot answer these questions without significant ETL changes. Redesign it.

Summary

Forty columns in. Zero useful answers out.

Practice This Problem

Solve this Data Modeling problem with real code execution. DataDriven runs your solution and grades it automatically.