# A regulatory audit consumer needs to reproduce the exact reporting numbers a regulator saw 90 days a

Canonical URL: <https://datadriven.io/problems/a-regulatory-audit-consumer-needs-to-reproduce-the-exact-rep-1cbd307d>

Domain: Pipeline Design · Difficulty: medium

## Problem

A regulatory audit consumer needs to reproduce the exact reporting numbers a regulator saw 90 days ago. The curated table is plain Parquet, so the historical state has been overwritten by compaction since then. Apply the section's snapshot-isolation framing and replace the plain Parquet table with a lakehouse format that supports the time-travel capability, retaining at least 90 days of snapshots.

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