What Never Arrives

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

Domain

SQL

Difficulty

easy

Seniority

mid

Problem

Our ingestion pipelines read raw records and write cleaned ones, and each job stamps its own run status, so a run that finished shows up as 'success' in whatever mix of upper and lower case that job happens to use. Across the runs that finished successfully, find the pipelines losing the most records between what they read and what they wrote, biggest losses first.

Summary

Every run reads more than it delivers. Find the pipelines bleeding the most between the door and the destination.

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