# A logic bug corrupted 3 days of a 2-year partitioned table

Canonical URL: <https://datadriven.io/problems/a-logic-bug-corrupted-3-days-of-a-2-year-partitioned-table-df739b16>

Domain: Pipeline Design · Difficulty: medium

## Problem

A logic bug corrupted 3 days of a 2-year partitioned table. Reprocessing all 2 years to fix 3 days is wasteful and risks the SLA. Design a backfill that re-computes only the affected partitions, idempotently.

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